It’s close to midnight on June 20 of this year and I am lying in a bed in the Riverside ward of London’s Charing Cross Hospital.

The previous day a tumour had been removed from my colon in a six-and-a-half hour operation. My surgeon, Mr Paul Ziprin, the lead for colorectal cancer at the three large London hospitals that make up Imperial Healthcare, had reported that all had gone well. My boyfriend David had alerted this good news to waiting friends on a WhatsApp group.

Prematurely, as it turned out.

The next afternoon when a nurse tried to get me out of bed to sit in a chair, I nearly fainted. My oxygen levels were not as they should be, but all seemed well enough for first my son Sam, then David to leave my bedside and head home.

A few hours later my hospital bay had its curtains closed and began to fill with urgent-looking doctors and nurses — Mr Ziprin had been called and had ordered an X-ray and a CT scan.

Alexandra Shulman survived breast cancer three years ago, but has now been diagnosed with colon cancer

Alexandra in hospital, when she underwent a six-and-a-half hour operation to remove a tumour from her colon

It was then that a large pulmonary embolism (blood clot) was found in my lungs, something that can happen after surgery. As a result, my oxygen levels were getting increasingly worse and I had significant right-sided ventricular heart strain.

Strangely I didn’t feel at all ill, but the staff made me nervous by saying I could phone David and ask him to return at this late stage of the night.

‘But I’m not going to die tonight am I?’ I asked one of the doctors. His answer was not reassuring. It was long and convoluted and all I took in was that it wasn’t 100 per cent the case that I would stay alive.

Almost immediately the room was awash with whispering nurses who bundled me up and rushed me through the hospital corridors into intensive care.

I am someone who previously regarded myself as pretty healthy – closer to the invincible end of the sliding scale than the vulnerable. My mother is still thriving at 97. My father died at 90. Neither had ever had cancer.

However, three years ago I was diagnosed with a breast cancer, which was treated by a lumpectomy (leaving my breast intact), radiotherapy and hormone therapy. It was the first time I felt real fear about my health. But, nevertheless, I considered the odds of making relatively old bones were in my favour.

So it was with a casual attitude that I took the poo test sent out by the NHS bowel cancer screening programme to everyone over 54 and posted the envelope off.

After all why should I worry? I had none of the symptoms listed as potential warning bells – bleeding, bloating, stomach cramps.

When, a week later, I got a letter saying that further investigation was needed, I was concerned, but only slightly. It could be a polyp. Probably was a polyp. I’d had a colonoscopy ten years before and it had all been fine.

However this time the colonoscopy, where a camera is inserted into the colon, was not fine.

As the doctor halted the investigation and asked a colleague to come over and put pressure on my abdomen, I remembered the moment my breast cancer was found during an ultrasound. I was pretty sure they had found something similarly unpleasant.

Was it cancer? ‘Yes,’ she said. ‘There is an obstruction here which I can’t get past. And it looks like a cancer.’

From that moment I was immersed in the sometimes seemingly impenetrable maze of waiting for biopsy results and hospital appointments that any cancer patient is familiar with.

‘The next weeks were a horrible wait. As someone used to being in control, I found it extremely difficult not having any say over one of the most serious events of my life’

When I met my surgeon, he explained it was a major operation, but he hoped he would be able to use the ‘da Vinci robot’ (such a heartening name) which enables the surgeon to operate through tiny keyholes rather than slicing open the whole area.

The next weeks were a horrible wait. As someone used to being in control, I found it extremely difficult not having any say over one of the most serious events of my life.

I tried to carry on as normal, but hanging over my days was the grim knowledge that I had colon cancer and I was going to have a major operation.

The first thing I thought of when I woke each morning was the operation. Everyone I spoke to said encouragingly that it was a simple little thing. They all knew someone who had had bits chopped out of their colon and were now right as rain.

My oldest friend said, with tremendous conviction, based on absolutely no knowledge, that nowadays it was just like having your tonsils out. Another said that, in the event I would need a stoma bag, I should remember the Queen Mother had had one. This piece of information was not entirely welcome.

It was difficult for friends and family to say the right thing. Either they seemed to downplay it or made me more frightened. I worried in some karmic way that, because I had been fortunate in how my breast cancer had turned out, I might not be so this time.

I grew increasingly nervous during the four-week wait. Any moment I wasn’t doing something I would just worry.

One morning, feeling desperately sad, I visited the Maggie’s centre at Charing Cross Hospital, a place where anyone with cancer can go for support.

When I spoke to a counsellor there about how I was feeling, I realised what I really minded was being a person who needed to be in that building at all. Ludicrously I thought it wasn’t fair, as if fairness has anything to do with it.

It was the only time throughout the whole thing that I cried.

David tried to reassure me that I was catastrophising, that it was all going to be alright, however, a few days before the operation in a pre-op check-up my usually low blood pressure was so high that the man taking it told me I wouldn’t be able to be operated on unless I did something about it.

I asked him to take it again and again, trying my yoga breathing techniques, listening to soothing Joan Baez songs… no shift. So I booked an urgent appointment with my GP who immediately stepped up and gave me every anti-anxiety and blood pressure medication I could wish for. I choked them down by the handful.

By the time I was waiting to go into theatre I just wanted it to be over, eager for the blissful nothingness imparted by the general anaesthetic.

In all my worrying it had never once entered my head that 36 hours after the operation, I’d be in intensive care, battling a blood clot on my lungs.

Astonishingly, when I was made aware there was a possibility I might not survive the night, I don’t remember feeling frightened. Sad and surprised, definitely.

Alexandra in her garden at home. The former Vogue editor says that after leaving hospital she was ‘happy to be alive, happy to be in my wonderful home, so aware of the love of family and friends’

Perhaps it was the morphine pump attached to me (although I wasn’t using it) or the oxygen or possibly shock, but despite being of an anxious disposition, I didn’t experience any of the symptoms I am well acquainted with as a sufferer of panic attacks – icy terror that seeps through your body, a sickening dizziness, a sensation of a thread being pulled tight in the brain so that it might snap.

There was none of that. I felt only a kind of disbelief that this was happening. That this might be the end of things.

On one level being moved into the intensive care ward was reassuring with its ratio of one nurse to two patients. On another it was hard to avoid the thought that I was only in that place because this was serious.

I couldn’t see how many other patients were in the ward because everything I was wired into kept me prone, but I could hear their sometimes distressed shouts. It was a noisy place, filled with urgency.

About six o clock the next morning Mr Ziprin appeared, before heading off to another hospital for a day’s surgery.

He said he was sorry this pulmonary embolism had happened, but it can do. It was bad luck. He was in favour of keeping going with the blood thinners, but there would be a multi-disciplinary meeting including teams like respiratory and cardio which would also have an opinion.

A couple of hours later another doctor (there seemed to be millions) informed me that the clot was too large to leave in place.

‘It’s about as a big a mass as you can get,’ he told me both terrifyingly and, I felt, unnecessarily. The team had convinced my surgeon they should intervene with a procedure that involved threading a line into the vein from my groin to get rid of it. But – and I got very used to these ‘buts’ – this would carry a risk because I had so recently had a long surgical procedure under anaesthetic.

Ludicrously, that morning a nurse appeared with a fluffy dog of some description in her arms asking if I would like to cuddle it. ‘Some people find it reassuring,’ she said sweetly. Anyone who knows me would understand this was not the sedative I was after.

I wanted to cry. I thought that might help in some unidentifiable way, but at no point did a single tear appear, even faced with these two possibilities – a clot in my lung too big to leave, or an operation that post-surgery might be additionally life threatening.

I was appalled and miserable.

How lucky I was to have David and Sam with me throughout that day, both appearing so calm and encouraging.

I kept looking at my son’s huge brown eyes and thinking how unfair it was that he had to experience what must be so frightening for him, too. But he only smiled and spoke gently to distract me.

‘I probably won’t die,’ I said holding their hands. ‘But if I do, you have to know how much I love you and know you will be alright.’

Neither was foolish enough to tell me it was nonsense to talk like this.

By mid-afternoon two doctors came to check my heart. It was they informed us, in pretty good shape which was fantastic news because this persuaded the vast medical team that it wasn’t worth taking the risk of the procedure.

Two days later, I was moved into a regular four-bed ward for women only. From my bed by the window I spent hours watching the endless stream of planes coming in to land at Heathrow.

All day and night bells went off, usually because somebody’s drip had finished or their arm was in the wrong position.

Although my embolism was being managed by the blood thinners, my bowels were, as Mr Ziprin said, stubbornly ‘sleepy’. It was possible there was a kink and they might have to reoperate, although he hoped not. As did I!

He sent another senior member of his team in to check me who said – joy of joys – that he was all for ‘masterful inactivity’.

Every day I was taken to X-ray to see if the dye I had swallowed had progressed through my body and every day, there was no sign of it in my colon.

Unless this happened I would not be able to go to the toilet. They wouldn’t be able to leave things as they were for very much longer.

By Day six, as I lay on the X-ray table, I sang the Sinatra song Luck Be A Lady to myself, hoping this time my fortunes would change.

I was fed up with the tube down my nose sucking gruesome liquids out of my stomach. I loathed dragging a catheter around the wards as I tried to do some exercise to encourage my body to get its act together.

I hated the long nights when I couldn’t sleep, and couldn’t move because of all the tubes and instead streamed box sets on my iPad, waiting till dawn when the ward would come alive with the tireless night-shift nurses doing their rounds before changeover.

And my luck did change that very afternoon or at least my colon decided to wake up, and slowly, very slowly, I was on the road to recovery, each day losing another wire or drip from my body.

Two weeks after the operation, I was out of the hospital gown and dressed in my clothes and David came to take me home.

What bliss it was to sink into my own bed and look out at the leafy green of the park opposite. What pleasure to wash in my bathroom with my favourite shower gels even though my stomach and arms were still covered in dressings.

Initially I was simply happy. Happy to be alive, happy to be in my wonderful home, so aware of the love of family and friends. And a few weeks later absolutely delighted that tests showed I needed no further cancer treatment, undoubtedly because of the early diagnosis.

There is still a blood clot in my lung, but I’ve been told it will dissipate with blood thinners.

However, this experience has changed how I feel about life.

I no longer feel I’m wrong to catastrophise — in the end the whole affair brought with it more horror than I expected.

For weeks I couldn’t sleep at night. My thoughts continually flashed back to the hospital ward and fears of another operation, no matter how hard I tried to distract myself.

I now know that however much friends and family might love and support you, there is nothing they can really do when you’re seriously ill. Endless concern, heart emojis, and bunches of flowers can only go so far.

And even now, as I go about the day, I see everything through the filter of this experience: I feel vulnerable and fragile and no longer so certain of living for decades more.

I think of practical things like money and realise there needs to be a plan A that covers me making a respectable old age and a plan B for that not being the case.

I feel more frail and fearful. I worry about tripping as I walk along the street and starting an unstaunchable bleed.

Every pain and ache makes me think something is going wrong again. And then I chide myself for being so melodramatic when so many people are much sicker than I have been.

After any kind of life-threatening event some people make radical changes to their lives, but I have realised how much I like mine how it is. I love my family and thoroughly enjoy my work. I know how fortunate I am.

Yet even so, there is a small part of me that is still waiting for an epiphany, something that would make me drastically reassess my life.

Fans of the late, great Dr Michael Mosley will be graced with one last fantastical documentary fronted by the health guru.

Filmed last year, the three-part Channel 5 programme sees the former Mail columnist decode the marvels of the human body – and discover everything from why bones break as we age, to pioneering cancer treatments.

Dr Mosley, who died from heat exhaustion aged 67 while on holiday in Greece, puts his own body under the microscope, undergoing experiments to test his heart health, saliva production and how his body copes with a dip in freezing waters. 

In the first installment, to be broadcast at 8pm on Thursday, Dr Mosley heads to Fife to meet Thomas, who suffers a common neurological condition, and is about to undergo pioneering brain surgery.

The 71-year-old suffers essential tremor, which affects roughly a million Brits and causes involuntary shaking or trembling.

Michael Mosley, who died this summer while on holiday in Greece , puts his own body to the test in the three-part series, testing his heart health, his saliva production and even taking a freezing dip himself

To test out a new heart disease predictor, the former Mail columnist steps forward for the procedure – which sees him have dye injected into his bloodstream so that his blood vessels show up on the CT scan.

Essential tremor is nearly ten times more common than Parkinson’s and tends to affect people over the age of 65. 

But for Thomas, symptoms began in his forties, when he first noticed his right hand shaking. 

By his mid-fifties, both hands, as well as his head, were shaking – and it just continued to worsen.

But now, Thomas is off to Dundee to receive a potentially life-changing surgery. 

The innovative procedure uses a beam of ultrasound waves to zap a tiny cluster of cells in a part of his brain called the thalamus, which is involved with movement.

Doctors hope this will create a circuit breaker that will stop Thomas’s brain from sending out too many confusing messages that cause his uncontrollable tremor. 

Fitted with a head brace to help keep him still, Thomas is kept awake throughout the surgery to ensure the beam doesn’t impact the parts of his brain that control his speech. 

If it strays even a fraction, he could be left unable to speak – or paralysed. 

To test his brain function after each round of the ultrasound, Thomas’ doctors have him draw a spiral on a piece of paper. 

The three-part series sets out to decode the marvel of design and engineering that is the human body, inviting viewers to see our bodies in new ways and understand how they work and how the body changes as we age

In the first episode, Dr Mosley heads to Dundee to meet tremors sufferer Thomas who is about to undergo pioneering brain surgery

At first, he’s barely able to make a mark on the page. 

But after seven rounds, his hand has stopped shaking enough that he is able to make a full spiral.  

‘I’m so grateful,’ Thomas says – ‘I noticed a change right away. I’ve improved way more than I thought I would.’

‘It’ll make a life-changing difference.’ 

Later in the episode, Dr Mosley meets 76-year-old Allen, who is about to learn if his experimental cancer treatment has been a success. 

Allen was diagnosed with stage 4 lymphoma – a type of blood cancer – a few years prior. 

‘They said that there wasn’t really much they could do to cure me,’ he explained. 

Prior to his diagnosis, Allen was a policeman in London, and spent nine years as Princess Diana’s personal protection officer. 

He started noticing symptoms of his cancer once he’d retired to Dorset, around the same time a family of Ukrainian refugees came to live with him. 

After his diagnosis, they decided to stay and help care for their host.  

‘I’d already planned and paid for my funeral,’ Allen said. 

‘I didn’t think I’d be around much longer.’

But then, Allen was thrown a lifeline by his medical team in Southampton; a treatment known as CAR T-cell therapy. 

Throughout the episodes, the doctor continues to track down answers to burning questions such as why do we get creaky joints? What happens when we catch the flu? Can we help our brains stay fit as we age? How do doctors replace a hip?

The revolutionary new cancer treatment works by boosting the body’s immune system, helping it to spot and fight cancer. 

T-cells – the body’s fighter cells – are removed, modified in the lab and re-injected into the bloodstream. 

These genetically edited cells now have a turbo-charged ability to track down and eradicate cancer cells. 

The approach doesn’t work for everyone, but Allen luckily receives brilliant news at his check-up; he’s in complete remission. 

Previously littered with cancerous tumours, his scans are now showing up clean.

Thanks to breakthrough treatments like this, Dr Mosley explains, we’re now six times more likely to survive cancer than we were 40 years ago – although one in two of us will be diagnosed with it in our lifetimes. 

Similarly astonishing technologies have emerged in recent years that tackle another major health concern for Brits – heart disease.  

Almost a quarter of all deaths in the UK are due to cardiovascular problems.

But a new test developed by researchers at the University of Oxford claims to be able to detect heart problems long before you have any symptoms. 

By looking at the fat that surrounds the heart vessels, scientists are able to spot early signs of infammation in the arteries, which could indicate a heart attack later down the line.

 To test it out, Dr Mosley steps forward for the procedure – which sees him have dye injected into his bloodstream so that his arteries show up on the CT scan. 

The episode also sees the doctor bravely sign up to a slightly more bracing experiment – a cold water swim.  

Speaking to cold water devotees – as well as trying it out himself – Dr Mosley reveals that when you swim in cold water, your arteries narrow – making your heart work harder to pump blood, strengthening its muscles. 

The plunge also releases hormones that are said to increase the body’s metabolic rate and boost your mood. 

Some regular swimmers even claim it helps with immune function as well – stopping them, ironically, from catching common colds. 

Finally, Dr Mosley examines why our bones become more brittle as we age. 

To investigate bone health, he travels back to the University of Oxford – this time to meet with Professor Sue Black. 

She explains that bones – while they may look solid from the outside – are actually very much alive and moving on the inside. 

As we age, the hormones such as estrogen that feed these bone cells begin to lessen. 

After menopause, however, estrogen levels drop – causing the bones to become rapidly weaker. 

Microfractures begin to form, which often fail to heal themselves. 

The condition – known as osteoporosis – is incredibly common: affecting one in five women and one in 20 men.  

To protect our bones as we age, we need to consume plenty of calcium and vitamin C – as well as continuing to do weight-bearing exercises like running and dancing.

The episode concludes with Dr Mosley agreeing to have a camera inserted through his nose to look at his voicebox – and revealing the shocking fact that humans produce enough saliva each month to fill an entire bathtub. 

In the next installment of the docuseries, he’ll look at hip replacements, stress and three things you can do at home to reduce blood pressure without joining a gym. 

How many times a day should I go?

Are there other signs I’m over- or under-hydrating?

Per

, clear pee can be a sign that you’ve drank too much water.

Our planet is changing. So is our journalism. This weekly newsletter is part of a CBC News initiative entitled “Our Changing Planet” to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page.

Sign up here to get this newsletter in your inbox every Thursday.

This week:

• How oceans could be used for carbon capture on a big scale
• Dam! Beavers pose a methane problem in the Arctic
• Humidity makes a sweltering apartment that much harder to live in

How oceans could be used for carbon capture on a big scale

Scientists have said we’re poised to overshoot the 1.5 C warming target enshrined in the Paris Agreement, and that in order to return to 1.5 C by 2100, we would need to remove vast amounts of carbon dioxide from the atmosphere.

Carbon capture from smokestacks or the air, using technology and tree planting, has received a lot of attention and funding. But last week, a few hundred scientists around the world argued that more attention should be paid to carbon capture in the ocean.

“The ocean’s carbon content is 50 times larger than what is in the atmosphere. Its sheer size also means that ocean-based climate solutions can be scaled to significantly mitigate climate risk,” they wrote in a letter posted on the web page of Ocean Visions, a non-profit umbrella group for universities and oceanographic institutions focused on ocean-climate restoration solutions.

The problem? Even scientists know little about the effectiveness, risks or impacts of ocean carbon capture solutions. 

Kate Moran, president and CEO of Ocean Networks Canada and a spokesperson for the scientists who wrote the letter, said more information is crucial for making policy decisions about ocean carbon capture.

“We do need to, as a collective community, get behind research needed to understand these issues, and it’s pretty urgent,” she said in an interview from the Canadian Coast Guard ship Tully off the coast of B.C., where she is doing some of that research.

The letter was signed by a number of scientists from the Canadian firm Planetary Technologies, including its chief ocean scientist, Will Burt. Planetary Technologies ran its first ocean tests of its carbon capture technology in Halifax harbour this week (see photo above).

Burt hopes the letter helps the public “build some confidence that what we’re doing is … widely believed scientifically to be worth exploring.”

WATCH | Scientists hope antacid could help relieve climate change

Scientists hope antacid could help relieve climate change

Halifax Harbour is getting a dose of Tums to see if that will help remove carbon from the atmosphere. Paul Withers has the story.

By now, you might be asking, “OK, but what kinds of solutions are we even talking about?” 

They fall into two main categories: biotic and abiotic.

Biotic ocean carbon removal is similar to planting trees on land to absorb CO2, except it involves marine or coastal ecosystems and plants. The carbon they store is called blue carbon, and it can involve:

Seaweed or “macroalgae” such as kelp. The carbon can later be sequestered — for example, by sinking it to the ocean floor. (That’s one of the solutions Moran was researching on the Tully last week.)

Microscopic organisms called microalgae or phytoplankton, encouraged to grow by fertilizing the ocean with nutrients such as iron.

Plants in coastal ecosystems, such as tidal salt marshes, mangrove forests or seagrass meadows. Restoring degraded coastal ecosystems doesn’t just store carbon, it also reduces emissions from sources like erosion.

Abiotic solutions include:

Ocean alkalinity enhancement. This is being tested by Planetary Technologies. It involves adding “antacids” made of rock dust, such as magnesium hydroxide, to the ocean to neutralize dissolved CO2. This converts the CO2 into stable minerals and salts, effectively removing it from the carbon cycle. Like a sponge that’s been squeezed out, the water regains the capacity to absorb more CO2 from the atmosphere. In the photo above, you can see Dalhousie University researchers taking measurements from a boat after the antacid was added to the water, along with a red dye that helps track how the antacid spreads. Burt says this technology should also reverse ocean acidification that harms coral reefs and shellfish.

Electrochemical ocean carbon dioxide removal. This technology uses electricity to separate seawater into acidic and alkaline solutions. Each of those solutions uses a different method to remove CO2 from seawater (one of them is very similar to ocean alkalinity enhancement). California-based Captura and Montreal-based Deep Sky plan to test this technology in eastern Quebec in 2024.

Planetary Technologies’ Burt said that while reducing emissions is by far the best tool for tackling climate change, “we’re going to need more than that.” 

Ocean carbon capture “could be a really key player.” 

— Emily Chung

Old issues of What on Earth? are here. The CBC News climate page is here. 

Check out our radio show and podcast. This week, meet the people doing the dirty work of planting millions of trees, one by one, across Canada. What On Earth airs on Sundays at 11 a.m. ET, 11:30 a.m. in Newfoundland and Labrador. Subscribe on your favourite podcast app or hear it on demand at CBC Listen.

Watch the CBC video series Planet Wonder featuring our colleague Johanna Wagstaffe here.

Reader feedback

Gaille Musgrove responded to last week’s story on invasive species: 

“I live north of Toronto in a township called Adjala-Tosorontio. I love it here. Unfortunately, I have invasions of all kinds of plant species that I have never seen before. Something called ground clover (no relation to real clover) has spread all over my property. It choked out my grass and is invading my gardens. We also have something called dog strangling vine, which has pulled down a fence and killed many trees. 

“In the 46 years that we have lived here, we have lost all of our butternut trees, all of our beautiful beech trees and now something is eating our spruce trees. It is very distressful.”

Write us at whatonearth@cbc.ca. 

Have a compelling personal story about climate change you want to share with CBC News? Pitch a First Person column here.

The Big Picture: Beavers pose methane problem in the Arctic

Climate change is helping beavers colonize the Arctic, and those beavers are in turn causing more climate change. A study by Alaskan researchers that looked at aerial and satellite photos of Alaska’s Arctic tundra between 1949 and 2019 (see below) found that dams built by beavers created 11,000 new ponds between 1980 and 2019.

A new study by the same team finds those ponds are releasing methane, a powerful greenhouse gas, accelerating climate change. The methane is produced as vegetation flooded by the dams rots in the absence of oxygen, and as the spreading water thaws the surrounding permafrost. The researchers say this means beavers in the Arctic will initially increase the release of methane, although they don’t know what the long-term impacts will be.

Interestingly, while beavers may be bad for climate change in the North, they’re being recruited to protect against the impacts of wildfires and droughts in places like California. Research shows that areas with beavers are more resilient to wildfire impacts and have more open water during droughts compared to areas without beavers.

Hot and bothered: Provocative ideas from around the web

• Filmmakers have launched a petition calling on Toronto’s International Film Festival to drop sponsorship from RBC, noting it’s one of the world’s biggest financiers of fossil fuels.

• A California high school is offering paid student internships for climate action with the aim of preparing the students for green jobs. Bonus: The students have saved their district $850,000 US on a $2.9-million energy budget.

Humidity makes a sweltering apartment that much harder to live in

On a hot summer day, the air in Sridharan Vankeepuram’s room can be nearly unbearable.

“It feels like a furnace inside,” he said.

His small bedroom — crammed with a single bed and desktop computer — doesn’t get much cooler at night, especially when it’s humid, as is often the case during a Montreal heat wave.

Vankeepuram has spent the past two years in an aging brick building on the western edge of Montreal’s downtown, while completing his MBA at Concordia University. One day in July, Vankeepuram’s room felt like it was 39 C when taking the humidity into account.

To better understand the challenges of living in extreme heat as the climate changes, this summer CBC News installed sensors in 50 homes that were either wholly or partly without air conditioning across five Canadian cities, including Montreal.

(CBC used “heat index” to measure the combination of air temperature and humidity, rather than humidex, a similar index developed in Canada.)

The sensors took temperature and humidity readings every 10 minutes. In some places — particularly in apartments in Toronto, Windsor and Montreal — the humidity made the residences feel much hotter. Winnipeg and Vancouver, which tend to have drier heat, were the other two cities featured in the project.

For half of the 56 days measured, Vankeepuram’s room didn’t drop below 26 C, the threshold considered dangerous for seniors and those with pre-existing conditions if they’re exposed to it for a prolonged period. And Vankeepuram’s room consistently felt even warmer, because of the humidity.

Knowing he would move out after graduating, Vankeepuram didn’t invest in an air conditioner. On the worst days, he took multiple showers or brought a bucket of ice water into his room.

For others, the consequences can be more dire. Humans cool down by sweating, but when the air is saturated with moisture, that doesn’t work as well.

“The more humid it is in the air, the harder it is for that process to occur,” said Prof. Daniel Gagnon, a researcher at the Montreal Heart Institute. “We might still produce sweat, but instead of it evaporating, it will drip off onto the floor and then we lose all of its cooling power.”

Gagnon, an associate professor at the school of kinesiology and exercise science at the University of Montreal, reviewed CBC’s data and found it striking that although Montreal escaped the worst of the Canadian summer’s heat, the temperatures inside often felt like more than 30 C with the humidity factored in.

“We need to factor in humidity as well, because a given temperature might be comfortable if it’s very dry, but become very uncomfortable if it’s very humid, and the body’s response to those environments will also be different,” Gagnon said.

Research isn’t conclusive on whether humidity increases the likelihood of mortality in cases of extreme heat, but it nevertheless puts strain on the body. 

During a historic 2018 heat wave, 66 people died in Montreal — and 80 per cent of those people died in their homes.

Gregory Walton, a 51-year-old who lives in an apartment in Windsor, Ont., said nights are especially difficult. In his apartment, the temperature almost never dropped below 26 C during the period CBC monitored and, with the humidity, it felt like nearly 32 C on one particularly muggy day.

Overall, in Montreal, Toronto and Windsor, high rates of relative humidity sometimes added as much as five to seven degrees to how hot a residence felt.

Here are the highest heat index measures our sensors recorded, by city:

• Windsor: 39.

• Montreal: 39.

• Toronto: 38.

• Winnipeg: 37.

• Vancouver: 34.

Climate scientists say hotter, more humid summers are likely in the coming years, as the planet warms, largely because of the burning of fossil fuels.

According to Environment and Climate Change Canada, a humidex in the mid- to high-30s is when the average healthy person should be more careful. Above 40 is considered extremely high and all unnecessary physical activity should be avoided.

Dr. David Kaiser, associate medical director at Montreal Public Health, said over the long term, better urban planning and changes to housing will help bring down the heat — and humidity — indoors.

In the more immediate term, Kaiser said the most at-risk would benefit from having an air conditioner. British Columbia recently announced a $10-million program for free air conditioners for those most vulnerable to the heat.

“I think it’s important from a health perspective that if you have an air conditioner at home and it works, you’re not going to die in a heat wave,” Kaiser said.

— Benjamin Shingler

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Editor: Andre Mayer | Logo design: Sködt McNalty