Whether you’re an out-of-shape snow shoveler, a hearty winter runner or a New Year’s Day polar bear dipper, Brock University’s Dr. Freeze has advice on how to deal with frigid temperatures.

Professor Stephen Cheung, known as Dr. Freeze for his cold weather-related research.

Professor Stephen Cheung, who runs a research lab at Brock that can simulate -30 degree temperatures, says precautions need to be taken when doing physical activity outdoors.

As a Canada Research Chair in Environmental Ergonomics, Cheung is the country’s leading expert on how the body handles extreme temperatures.

He listed four common winter activities and gave his advice for those venturing outdoors.

Snow shoveling:

“With many of the stories you hear about people having heart attacks when shoveling snow, it’s not because of the cold, it’s because of the high exertion,” Cheung said. “It really comes down to people who may not regularly exercise going out and trying to clear the snow as rapidly as possible.”

He said people who don’t often exercise need to take it easy when shoveling and treat it as the weightlifting workout that it is.

Outdoor workouts:

“For people who still want to get outside and exercise by running or biking or cross-country skiing, besides needing to be careful not to slip and slide, from a physical standpoint you want to keep a steady pace,” Cheung said.

“It’s safe to exercise, but rather than doing those really hard efforts like intervals where you’re building up sweat and then cooling off, go at a light, but steady pace.”

He said research has shown that heavy breathing in extremely cold temperatures isn’t going to damage your lungs.

“The body is very good at warming up the air before it hits your lungs,” Cheung said.

Polar Bear dips:

There’s a long tradition of stripping down to bathing suits and jumping into a cold lake on New Year’s Day.

Cheung said for those with no heart issues, the brief cold-water plunges are not particularly dangerous, but it’s important to avoid drinking alcohol before you try them.

“That’s the worst thing you can do because it’s going to cause the blood vessels in your skin to open up so you’re going to lose more heat that way,” he said. “Alcohol will also decrease your perception of cold, so you’re not going to take the simple precautions after of trying to get yourself dry and warm.”

Walking on ice:

“A very big danger at this time of year is going out on the water before it freezes,” Cheung said. “It’s extremely dangerous falling into cold water. Water conducts heat 25 times faster than air, so even if it’s shallow and you’re just falling into a stream, your clothes are going to be wet and it’s going to cause you to lose heat a lot faster.”

Cheung said if you fall into cold water, it’s important to immediately get into dry clothing, “otherwise those wet clothes will suck away heat very, very fast.”