Research patient Lise Cloutier sits in the worlds only direct air calorimeter a machine that continuously and precisely measures how much heat is gained and lost by the human body at a University of Ottawa lab.Spencer Colby/The Globe and Mail

The cylindrical chamber at the University of Ottawa lab looks at once like a machine from the past and the future. It swings open at a seam, splitting in half to reveal its contents. Tubes and chains dangle from the ceiling and reflect off the aluminum-sheeted walls. Theres just enough room inside for a black metal chair, rigged with wires for data collection and padding for comfort.

The chamber is the labs pice de rsistance. Its the worlds only direct air calorimeter a machine that continuously and precisely measures how much heat is gained and lost by the human body.

Originally developed in the 1970s at Memorial University of Newfoundland, the calorimeter was mothballed in 1990, until Dr. Glen Kenny brought it back to life later that decade. He likened the process to finding a rare Corvette at the dump and then refurbishing it.

More than 1,000 people have sat in the chamber over the years, lending their bodies to science in pursuit of nailing down how, exactly, the body responds to heat under various scenarios. The reason we put the calorimeter back together is that its the golden key in understanding how the human system is going to react to heat exposure, Dr. Kenny said.

Glen Kenny, professor of Physiology and Research Chair in Human Environmental Physiology at the University of Ottawa.Spencer Colby/The Globe and Mail

The Ottawa lab is at the forefront of research globally when it comes to the impacts of rising temperatures on human health, particularly among vulnerable populations such as the elderly and those living with chronic illness. The U.S. military, mining industry, electric utilities and others have looked to Dr. Kenny for help developing heat-management and monitoring strategies to protect people working in hot environments.

Health Canada has also turned to Dr. Kenny for advice. In late 2018, the federal department tasked him with assessing the effects of an extreme heat event on the most vulnerable Canadians. This led to the launch of a multiphase study on prolonged heat exposure, indoor temperature limits and cooling centres.

The study has not yet been published, but the data is in. It provides clear parameters for safe indoor temperatures and it dispels some commonly held views on the efficacy of cooling centres during heat waves.

The findings will inform federal guidance for health authorities across the country as they create strategies to address the growing problem of extreme heat. According to Health Canada, roughly 80 per cent of local and regional health authorities are currently working to take a range of evidence-based action to protect health from extreme heat. The department is aiming to develop its interim guidance this year.

Time is of the essence. When the record-setting heat dome settled over B.C. and then crept eastward last June and early July, Canadians were confronted with the reality that heat is a silent and prolific killer with the power to overwhelm emergency services. It was the deadliest weather event in Canadian history, linked to at least 619 sudden deaths in B.C.

Nearly one year later, as the clock ticks toward another summer, the provinces coroners service has shed light on the circumstances of those who died. According to a death-panel report released Tuesday, people aged 70 and older accounted for two-thirds of the deaths. Almost all 98 per cent died indoors. The overwhelming majority of the victims had at least one chronic disease. Most lived in socially or economically deprived neighbourhoods. More than half lived alone.

Among other recommendations, the report calls for a co-ordinated provincial heat-alert system and the adoption of community wellness checks for the most vulnerable.

Its certainly worth looking back, because a lot went wrong last summer. People in distress couldnt get through to 9-1-1 dispatchers. Some got a busy signal or were put on hold. Some callers who did manage to get through ended up waiting several hours for an ambulance. At one point, every fire truck in Vancouver was out on medical calls.

B.C. report on last years heat wave is a grim reminder that we must better protect our most vulnerable

Cooling in new buildings, tree canopy vital during heat waves: B.C. coroner report

Several emergency-services agencies in B.C. have since upgraded their heat-response plans and increased their staffing levels. B.C.s E-Comm system, which provides dispatch services for police and fire departments, rolled out a new call-transfer process that it says has materially improved answering capacity. BC Emergency Health Services is piloting a new app that allows for on-scene video consultations between a patient and clinician at the dispatch centre. Vancouver Fire Services is training some of its staff in emergency medical response a higher level of care for many firefighters.

Its a good thing. The Pacific Northwest heat dome was a once-in-1,000-year weather event, but it wont be 1,000 years before the next one. As the world warms, episodes of extreme weather will increase in frequency, intensity and duration.

Just last month, a heat wave in India and Pakistan killed at least 90 people. And while B.C. was in heats fatal crosshairs last year, other parts of Canada arent immune. A 2010 heat wave in Ontario and Quebec killed at least 280 people. A 2018 heat wave claimed dozens of lives in Montreal.

To get ready for heat, we must first understand its assault on the body. Theres a lot we already know. We know that if a persons core body temperature reaches 40 C and continues to warm, critical systems will start shutting down. The brain will stop processing normally. The body will lose its ability to cool itself through sweating. The blood will thicken, forcing the heart to beat harder and faster. Breathing will become rapid and shallow. Organ systems will eventually fail.

The body's ideal internal temperature is 36.9 degrees Celsius. As core temperatures rise, our internal regulation turns to acute self-preservation that leaves the body vulnerable in many ways. Symptoms of heatstroke set in above 40 degrees Celsius internally; the American Physician Journal recommends rapid cooling and, if done in a timely manner, it can be 100 per cent effective.

We know that age is the single most important factor in terms of vulnerability to this sort of demise. With each decade, we lose roughly 5 per cent of our ability to thermoregulate to lose heat. We know that sweating causes evaporative cooling and is key to guarding against hyperthermia; high levels of humidity inhibit that evaporative cooling process.

We know that having certain underlying conditions, such as diabetes or high blood pressure, puts people at a greater risk of heat-related illness and death. And we know that it can take a while before the accumulation of heat in the body starts affecting our cells and organs; its usually not until about 24 hours after the onset of a heat wave that people begin dying.

Dr. Kennys latest research takes our understanding further. By studying real people with real health conditions in really hot temperatures for long periods of time, his team is able to make nuanced recommendations that go beyond existing, often one-size-fits-all advice.

This kind of work is extremely important, said University of Washington global health professor Kristie Ebi, a lead author on the Intergovernmental Panel on Climate Changes 2018 special report about the effects of global warming of 1.5 C above preindustrial levels. Were seeing heat waves at intensities we havent seen before. Were not prepared. We need to understand how to best protect people, particularly the most vulnerable.

Its the most vulnerable that Dr. Kenny is most concerned with. When he explains his findings, he refers to colour-coded graphs with dots representing study participants. He wants policy makers and individual Canadians to pay close attention to the dots that fall outside the clusters. You cant just look at the mean of a dataset, he said. What you need to be concerned about is the outliers. Those are real people. Theyre the ones who are going to collapse.

Roughly 100 people participated in the federally commissioned research at the Ottawa lab. The younger, control cohort ranged in age from 18 to 31, and the older, more vulnerable group ranged from 60 to 80. Among the older demographic, a subset had either Type 2 diabetes or hypertension an underresearched demographic in the area of prolonged heat exposure, Dr. Kenny said, owing to concerns around stress-testing vulnerable people in extreme conditions.

Three years in the making, the study has involved more than 2,400 lab hours.

On trial days, study participants put on shorts and a T-shirt, signed a consent form and got hooked up to some physiological recording devices. These included, among many others, a blood-pressure unit, an ECG machine, a body-temperature probe, a heart-rate monitor and a mask that measures oxygen consumption.

The subject then entered the study space, which consisted of two concentric cylinders (imagine one pop can inside another). The larger cylinder is about the size of a two-car garage, only taller. Thats the environmental chamber. It can be set to different temperatures and humidity levels to simulate various living and workplace scenarios. It regulates the conditions around and within the smaller, inner cylinder. Thats the calorimeter, where the nitty-gritty of the trials took place.

Heres how it works. Researchers measure the temperature and humidity of the air entering the chamber and coming out of it. They measure two sources of heat the heat produced by the body from simply being alive, and the dry heat the body absorbs from the hot air. Those two values, added together, equal the total amount of heat gained. Researchers then measure the moisture levels going in and out of the chamber to determine how much sweat was produced and evaporated. Thats the amount of heat lost. The difference between the heat gained and the heat lost is the amount of heat being stored in the body.

Housed at the University of Ottawa, the worlds only direct

air calorimeter is considered the key to understanding

the impact of extreme heat on the human body. Scientists

measure the temperature and humidity of the air entering

the chamber and coming out of it. They can then calculate

how much heat the body was able to shed through thermo-

regulatory processes such as sweating, and how much it

ends up storing. Storing too much heat can lead to illness or

even death.

1. The calorimeter, which is housed in an environmental

chamber (not shown), is equipped with software that

allows researchers to monitor and record the physiologi-

cal responses of a study participant exercising or at rest.

2. The temperature in the chamber is tightly controlled to

simulate hot conditions. Study subjects wear monitoring

devices, including a mask that collects expired gases and

helps determine the amount of heat produced by the

body due to metabolism.

3-4. By precisely monitoring air temperatures and humidi-

ty levels flowing into (3) and out of (4) the calorimeter,

researchers can measure the rate of heat-exchange

between the body and the environment. Using these

measurements and the rate of heat production described

in (2), the calorimeter can be used to quantify the

real-time accumulation of heat within the body.

kathryn blaze baum and john sopinski /

the globe and Mail, Source: Dr. Glen P. Kenny,

University of Ottawa, Human and Environmental

Physiology Research Unit

Housed at the University of Ottawa, the worlds only direct

air calorimeter is considered the key to understanding

the impact of extreme heat on the human body. Scientists

measure the temperature and humidity of the air entering

the chamber and coming out of it. They can then calculate

how much heat the body was able to shed through thermo-

regulatory processes such as sweating, and how much it

ends up storing. Storing too much heat can lead to illness

or even death.

1. The calorimeter, which is housed in an environmental

chamber (not shown), is equipped with software that

allows researchers to monitor and record the physiologi-

cal responses of a study participant exercising or at rest.

2. The temperature in the chamber is tightly controlled to

simulate hot conditions. Study subjects wear monitoring

devices, including a mask that collects expired gases and

helps determine the amount of heat produced by the

body due to metabolism.

3-4. By precisely monitoring air temperatures and humidi-

ty levels flowing into (3) and out of (4) the calorimeter,

researchers can measure the rate of heat-exchange

between the body and the environment. Using these

measurements and the rate of heat production described

in (2), the calorimeter can be used to quantify the

real-time accumulation of heat within the body.

kathryn blaze baum and john sopinski / the globe and Mail,

Source: Dr. Glen P. Kenny, University of Ottawa, Human

and Environmental Physiology Research Unit

Housed at the University of Ottawa, the worlds only direct air calorimeter is considered the key to

understanding the impact of extreme heat on the human body. Scientists measure the temperature and

humidity of the air entering the chamber and coming out of it. They can then calculate how much heat

the body was able to shed through thermoregulatory processes such as sweating, and how much it ends

up storing. Storing too much heat can lead to illness or even death.

1. The calorimeter, which

is housed in an environ-

mental chamber (not

shown), is equipped with

software that allows

researchers to monitor

and record the physiologi-

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How does the human body respond to rising temperatures? This one-of-a-kind lab in Ottawa is trying to find out - The Globe and Mail