Emergency doctors warned on Jan. 24, 2026, that frostbite can develop within minutes on exposed skin during the deep freeze gripping much of Canada, and that early rewarming — immersing the area in warm water for at least 30 minutes — is the most important first response.
A risk that ‘can happen to anybody’
As bitterly cold temperatures plunged much of the country into a deep freeze, emergency doctors and public health experts warned people to protect themselves from frostbite. Wind chills dropped below -30 C in Toronto and Ottawa, and one public health inspector in Thunder Bay, Ont., reported it was minus 47 with the wind chill on Friday.
In some parts of Canada where winters aren’t always this frigid, people may not realize frostbite is “a real risk that can happen to anybody” when the temperature drops, said Dr. Sahil Gupta, an emergency physician at St. Michael’s Hospital in Toronto. “I trained in Edmonton. We saw frostbite a lot more than I do here,” he said. “But with the cold spells that we have had, especially going into this weekend, I think we need to be prepared.”
What frostbite looks like
Frostbite happens when the skin freezes. The early stage is called frostnip, when there is not yet any permanent damage to the skin. “Mild frostbite tends to look sort of like a sunburn,” said Dr. Kate Hayman, medical director of the Toronto General emergency department at University Health Network. The skin often looks red, but can also be pale until it’s warmed up and then becomes red.
More serious frostbite is characterized by grey or “dusky” skin and sometimes blisters, Hayman said. The skin can also feel unusually hard and waxy, as well as tingly and numb, said Gupta. In severe cases, the skin turns darker blue or black — a sign the tissue is dying because cold-damaged blood vessels can no longer carry oxygen to the area, and amputation may be needed.
Frostnip and frostbite can affect any area of exposed skin, including the face, ears, hands and feet, according to Toronto Public Health, with fingers and toes of particular concern during prolonged exposure. Environment Canada notes frostbite can develop within minutes on exposed skin, especially with wind chill.
Prevention: layers, mittens and a car kit
“We’re urging everybody to limit the amount of time that they spend outside” during the extreme cold, said Marc-Antoine Deschamps, superintendent of public information for the Ottawa Paramedic Service. “If you have to go outside, it’s important that you dress in layers, that you put on multiple layers to really trap the heat close to your body.” He advised not forgetting a hat, neck warmer, gloves or mittens and boots that aren’t too tight, to allow good circulation.
Dr. Howard Shapiro, associate medical officer of health for Toronto Public Health, recommended choosing mittens over gloves because they keep the fingers warmer. People who must work outside should take regular breaks to warm up, Environment Canada advises.
People who are homeless are at especially high risk. “Amputation is much more common among people who are homeless than those who are housed,” Hayman said. “Early care is critical.” Toronto opened warming centres, including “surge sites,” to shelter people during the cold snap.
Matthew Bradica, a public health inspector with the Thunder Bay District Health Unit, urged people to take precautions even for “ordinary things” like errands — a flat tire can turn routine trip into an emergency — and to keep a car kit with extra layers, hats, gloves, jumper cables and a shovel. “You want to get out of the cold as soon as you possibly can.”
Treatment: warm water, then stay warm
“Getting out of the cold and early rewarming are the most important things that people can do,” said Hayman. Many cases are mild and can be managed at home: immerse the affected areas — usually hands or feet — in warm water for at least half an hour until the skin feels soft again, and keep the area clean in case there are wounds.
Seek medical attention if numbness or a change in skin colour persists after rewarming; blisters signal deeper injury, Gupta said. And once an area is warmed, Shapiro stressed, it must not freeze again: “That’s going to lead to more damage.”
In hospital, doctors can use circulation-improving medications — including iloprost and thrombolytics, the clot-busting drugs used for heart attacks and strokes. Both doctors said patients too often arrive days after exposure. “We really need to initiate treatment within 24 to 48 hours to reduce the risk of amputation,” Hayman said.
