This winter has had absolutely no chill.
The US has been experiencing intense, record-setting cold and persistent, widespread snowfall, creating life-threatening conditions in several regions.
Hospitals across the country are reporting a surge in cold-related injuries — from slip-and-fall fractures to cardiac events from snow shoveling and frostbite.
Frostbite is especially dangerous because the freezing process numbs nerves, preventing people from realizing they are injured until the damage is serious.
Dr. Emily R. Nadelmann — a board-certified dermatologist and clinical assistant professor of dermatology at the George Washington School of Medicine and Health Sciences and the University of Maryland School of Medicine — shares the frostbite signs to beware and the factors that increase your risk of developing it.
What are the four phases of cold exposure that lead to frostbite?
- Pre-freeze phase: Tissue temperature cools, causing blood vessels to constrict and blood flow to drop without the formation of ice crystals.
- Freeze–thaw phase: Ice crystals form inside or outside cells, damaging cellular structures. Tissue thawing during this stage can initiate inflammation and injury.
- Vascular stasis phase: Circulation becomes unstable.
- Late ischemic phase: This stage is marked by worsening inflammation, intermittent narrowing of blood vessels and blood clot formation that drive tissue death.
What are the key symptoms of frostbite?
“Early frostbite often causes intense cold, tingling, burning or sharp pain, which can progress to numbness as skin temperature falls below 50 degrees Fahrenheit,” Nadelmann said.
“Before rewarming, affected skin may first appear red, then turn waxy white and feel firm or ‘wooden,’ with the full extent of injury becoming clearer after thawing.”
First-degree frostbite is characterized by numbness, redness and white or yellow plaques, while second-degree frostbite brings clear or milky blisters.
Third-degree frostbite represents severe, deep tissue damage that results in blood-filled blisters. And finally, fourth-degree frostbite extends into subcutaneous fat, muscle and bone, often leading to permanent tissue loss.
“Frostbite can occur on any part of the body exposed to extreme cold, but it most often affects the extremities and facial areas, where blood flow is reduced to protect core temperature,” Nadelmann explained.
“Hands, feet, cheeks, ears and the nose are particularly vulnerable, with fingers able to freeze at warmer temperatures than the cheeks.”
How is frostbite treated?
Rapid rewarming is the cornerstone of frostbite treatment, said Nadelmann, who recommends immersing frozen skin in water that’s 99 to 104 degrees Fahrenheit for 20 to 30 minutes.
“Water should feel comfortably warm, slightly above body temperature, not hot,” Nadelmann advised. “If warm water is unavailable, air rewarming may be used.”
Be sure to remove jewelry and tight clothing before swelling begins.
Since frozen tissue cannot sense ongoing injury, you should avoid walking, bearing weight and rubbing the affected areas.
Emergency care may be needed if the frostbite is more severe than superficial frostnip.
“Patients with deep frostbite, particularly when it extends to the middle joints of the fingers, should be taken to centers equipped for rapid rewarming, advanced imaging and treatment that dissolves dangerous blood clots,” Nadelmann said.
“Severe cases may require care at specialized burn centers.”
It’s imperative to seek treatment within the first 24 hours to reduce the risk of amputation.
How does frostbite differ from Raynaud’s syndrome?
Frostbite isn’t the only temperature-sensitive condition.
Raynaud’s syndrome occurs when small arteries in the fingers and toes spasm and narrow in response to cold or stress, causing the skin to turn white or blue.
Unlike frostbite, tissue doesn’t actually freeze or form ice crystals. And Raynaud’s attacks typically only last a few minutes to hours.
“Unlike the reversible color changes and discomfort seen in Raynaud’s attacks,” Nadelmann said, “frostbite results in true cellular injury, inflammation and lack of blood flow, which can progress to tissue death and even amputation.”
Raynaud’s primarily affects women 15 to 30 years old due to hormonal factors and smaller stature.
The condition can heighten susceptibility to frostbite during cold exposure.
Which factors increase vulnerability to frostbite?
Besides Raynaud’s, peripheral vascular disease, diabetes, hypothyroidism and cardiovascular disease raise the risk of frostbite.
Smokers, those taking medications that reduce blood flow by constricting vessels, men, children, older adults, African-American or Afro-Caribbean individuals and anyone with a prior cold injury face higher odds of developing frostbite as well.
Risk significantly increases at altitudes above 5,000 meters, where oxygen is lower, and in very cold seawater, where human tissue freezes at 31 degrees Fahrenheit.
“Experts also recommend avoiding cold exposure when ill and steering clear of substances that further reduce blood flow, such as alcohol, nicotine, stimulants or certain medications,” Nadelmann said.
How can you prevent frostbite?
“Frostbite can be prevented by keeping exposed skin warm, dry and protected from wind while maintaining good circulation,” Nadelmann recommended.
“Wearing layered clothing, choosing mittens over gloves, using hand and foot warmers and avoiding tight garments that restrict blood flow all help, along with staying well-hydrated and nourished.”
When extreme cold hits, you should limit your outdoor exposure, regularly check your extremities for numbness or pain and promptly rewarm affected areas.
