Extreme exposure

Extreme exposure

What happens to the human body when it is stuck in a deep-freeze or caught in sweltering heat? A new Brock lab is studying the effects of extreme temperatures
December 2, 2009
Stephen Cheung
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Stephen Cheung
Courtesy of Brock University

It’s about 5°C in the chamber, and Geoff Hartley, wearing a bdefaultap tunic and sandals, is trying with numb fingers to put small pegs in small holes. It’s just another day of chillin’ out at the Brock University lab of Stephen Cheung, a world-renowned scientist who studies the impacts of extreme temperatures on the human body.

Hartley, one of Cheung’s graduate students, donned the charming outfit in August for a History Channel program on the Carthaginian commander Hannibal and his treks through Europe, circa 200 BC. The segment examined how soldiers might have functioned in the frigid mountains. After a half-hour of tasks and monitoring, Hartley’s fingers started aching, so Cheung halted the performance.

“Somebody’s got to do the data collection in the lab, so I guess I have a bit of value,” says Hartley, laughing. “I’ve been in the chamber quite a lot, but not with TV cameras.”

The Environmental Ergonomics Laboratory, a one of a kind in North America and one of only a three worldwide, features a three-by-three-metre environmental chamber with controls that can adjust the temperature to anywhere between –30°C and +50°C as well as the levels of humidity and oxygen. It also has a circular water-immersion facility, two metres in diameter, that can be made to feel like a hot tub or the cold Atlantic Ocean.

How temperature can affect the body — heartrate, sweating and shivering thresholds, dexterity and even the psychological impacts — has long fascinated Cheung. And when he entered graduate school at Simon Fraser University in 1991 under mentor Igor Mekjavic, he decided to pursue environmental ergonomics.

Cheung’s team has made numerous advances in survival/flotation suit design, temperature regulation during both heat stress and hypothermia and reducing heat stress during exercise for people with multiple sclerosis.

High school student Noah MacCallum prepares to be
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High school student Noah MacCallum prepares to be dipped in a cool tank of water as part of a lab demonstration.
Courtesy of Brock University

“We are learning how the body works, but pretty much every project we do can be applied to a particular context to make work or exercise safer or more productive,” says Cheung. “That’s certainly a thrill for me.”

Cheung also completed a project this year for the Canadian Olympic snowboarding team. But don’t ask him for details. “They would literally run me over with a snowboard, or worse, if I told you before the closing ceremonies,” he says.

David Lever, a Coast Guard officer at Search and Rescue headquarters in Ottawa, says Cheung’s work is invaluable for improving safety gear and saving lives at sea. “We’re able to apply this research to more than just medical science,” he says. “It’s actually helping us with the prediction of search and rescue survival times and is assisting manufacturers in making better products, such as life-saving equipment and clothing.”

Cheung will soon embark on a three-year multidisciplinary project with a team of public and private partners that is pooling resources to examine northern disaster scenarios, such as plane crashes or shipping accidents, in the hopes of improving survivability in the Arctic.

To start, Cheung is now seeking a volunteer willing to don a T-shirt and endure 24 hours at 5°C to measure the physiological and psychological impacts of prolonged exposure. He’s hoping a motivated mountain climber will rise to the challenge because it’s never been done, and considering Hartley’s brief encounter, Cheung might have to look beyond his grad students this time.