What Do Freezing Temperatures Do to Your Body?

Early detection is key when treating frostbite, says Robert Glatter, MD, an assistant professor of emergency medicine at Northwell Lenox Hill Hospital in New York City. Without proper medical care, frostbite can contribute to complications like sensitivity to cold, long-term numbness, joint stiffness, gangrene, and hypothermia, per Mayo Clinic. Seek medical attention if you experience signs of severe frostbite. These include white or blue-gray skin, loss of sensation or an inability to feel cold, joint and muscle malfunction, blisters that appear 24 to 48 hours after rewarming, or tissue that has turned black and hard.

How Do You Know When You’re at Risk for Hypothermia?

Hypothermia happens when your body loses heat faster than it can produce it, and your body temperature drops dangerously low (below 95 degrees F), according to Mayo Clinic. This drop in body temperature prevents your heart, nervous system, and other organs from working normally.

“Hypothermia is a medical emergency,” says Dr. Glatter. “As your body temperature drops, your heart, brain, and internal organs cannot function. Without aggressive resuscitation and rapid rewarming, you will ultimately not survive.” Glatter notes that one of the first signs of hypothermia is shivering (as your body tries to produce heat), followed by slower breathing and heart rate in the second stage, along with confusion and sleepiness.

“The insidious thing about hypothermia is that it often causes impaired cognition, which affects the ability to recognize what’s wrong, so the hypothermia can get worse,” says Bradley J. Uren, MD, an assistant professor of emergency medicine at the University of Michigan Medical School in Ann Arbor; Penn Medicine also describes this phenomenon. Dr. Uren and Glatter both note that the impairment can make someone look intoxicated, stumble, and speak incoherently — hypothermia mimics a stroke in this way — but checking your temperature can give some insight into where these symptoms are coming from.

If you’re sweating or wet for another reason your risk of hypothermia increases. (Remember: Snow melts, especially when it gets under your coat and onto your skin.) So if you’re a die-hard runner and have to get your miles in or plan to be outside and active in the snow, take precautions to stay dry. When the temperature drops, wear a synthetic base layer to wick away moisture, according to the Cleveland Clinic. The Cleveland Clinic then advises you to layer up; you can take these extra layers off and tie them around your waist as you start getting hot on your run.

“That’s your ideal way to protect yourself against not only the outside elements, but to help protect you from sweat that could inadvertently contribute to hypothermia,” says Uren. “Water, in any form, is the greatest enemy.”

Even if you’re planning to stay dry, being outside during extremely cold temps in inappropriate clothing can put you at risk for hypothermia.

What to Wear if You Have to Be Outside in the Extreme Cold

If you have to be outside, make sure you dress for it (and plan ahead so you can avoid being outside for too long). Regardless of the activity you’re doing outdoors (be it shoveling snow, walking your dog, or commuting to work), layering will keep your whole body warm in this kind of weather. “Go for looser rather than tighter layers, because it keeps a layer of air between the cloth. That air will stay warm and take longer to cool, as opposed to the cloth itself, which can cool down from outside temperatures,” Ford and the American Academy of Dermatology (AAD) note. In cold, wet weather, wear wool instead of cotton, because wool repels moisture and helps you maintain dry, warm air in your clothing layers, the AAD adds.

To protect your lungs, use a scarf or a ski mask (or even a pulled-up sweater to cover your mouth and nose), suggests Mayo Clinic Health System. Just as you do when layering clothes, keep a buffer zone between your face and the fabric to give the air a place to warm up before it hits your lungs, Ford says.

Don’t forget to wear a hat and gloves or mittens, either. Cleveland Clinic advises that, contrary to popular belief, you don’t lose any more heat from your head than from other body parts, but the head does have a large surface area of skin. A hat helps because you’re covering up more of that exposed skin. If he has to work outside, Ford wears a pair of thin gloves and then outer gloves, and slips hand warmers between the inner and outer gloves; the thin gloves protect his hands from potential damage from the hand warmers.

One area vulnerable to frostbite that many people tend to neglect is the skin around their eyes. Uren suggests wearing ski goggles to protect against the wind and retain heat if you must be outside in extreme cold.

Keep in mind that the air is very, very dry when it’s super cold, and will draw moisture from your body, causing you to lose fluids quickly. If you’re breathing hard while outside, be sure to keep water handy in a stainless steel, vacuum-sealed thermos to avoid dehydration.

Uren also keeps a shovel, emergency kit, zero-degree sleeping bag, and boots in his trunk during the winter in case of unplanned, emergency exposure to the elements.

How to Successfully Manage Chronic Disease in Extremely Cold Weather

If you’re healthy and have your skin and airways fully covered, you likely will be fine outside for 10-minute stints when the windchill is at or slightly below 0 degrees F, Uren says. But if you’re managing a disease, you may need to be extra cautious in extremely cold temperatures. Here’s why.

Asthma For anyone, inhaling extremely cold air exposes moist lung tissue to the cold and can cause airways to tighten and feel constricted. If you have asthma, you’re at risk of immediately feeling short of breath, wheezing, and coughing, according to Harvard Health Publishing. If you’ve been instructed to use a rescue inhaler, that can help. “But if you have difficulty breathing, you shouldn’t wait. Go to the nearest emergency department,” Uren says.

Diabetes Because of the body’s changes in blood circulation in the cold, blood sugar levels in folks with diabetes can be erratic, mostly in type 1 diabetes, but it’s also possible in type 2 diabetes, Ford says. If you’re feeling dizzy or weak when you come back inside, check your blood sugar. If you’re using insulin and you keep it in the car, bring it inside so the medication doesn’t freeze, per the CDC.

If you have diabetic neuropathy, or nerve damage, be aware that you may not be able to feel when your feet are getting too cold and you are at risk for frostbite, according to the University of Rochester Medical Center.

Arthritis Arthritis may act up in very cold weather. “I’m not aware if anybody has found a medical basis for it, but I see people having more joint pain,” Uren says. If you have to shovel snow, Ford suggests taking some anti-inflammatory drugs first and breaking the work into 10-minute shifts. Once you’ve warmed up inside and have feeling back in your hands, it’s safe to go out. If you know the cold is a trigger for your joint pain, talk to your doctor to have an action plan.

Autoimmune disease Raynaud’s phenomenon is a condition affecting blood flow that results in your fingers and toes undergoing extreme changes even in normal cold weather; your extremities may turn very white, then turn blue or red when they warm up. The causes aren’t well understood, Ford says, but it puts patients at greater risk for frostbite. Raynaud’s can occur on its own or in association with a variety of autoimmune diseases, particularly lupus, and less frequently with rheumatoid arthritis, past research shows. With Raynaud’s, it’s often painful to go out in cold weather, so you should limit your time outside and wear extra gloves and use hand warmers if you do go out.

Cancer If you’re in an immunosuppressed state, as those with cancer are, you’re more at risk for complications from communicable diseases like the cold and flu during the winter. In addition, those undergoing active cancer treatment may be more sensitive to harm from cold exposure because of anemia and dehydration, which can compromise their ability to maintain a healthy temperature, and they also may have neuropathy from chemotherapy, which increases the susceptibility to frostbite, according to Northwestern Medicine. It’s best to talk to your oncologist to discuss your specific cold weather risks if you have cancer.

Chronic obstructive pulmonary disease (COPD) Because every case of COPD is different, it’s important to pay attention to what your body is telling you. “Most people I take care of understand, ‘If I go outside and it’s colder than x degrees, I’m going to have a problem.’ Some have found that wrapping a scarf [around their mouth and nose] to breathe warm air helps, but that doesn’t work for everyone,” Uren says. If your COPD is poorly managed, plan ahead to stay inside and work with friends and family to make sure you have everything you need.

Heart disease Cold temperatures can add strain to your cardiovascular system, making your heart work harder, which can put you at greater risk of heart attack, according to Northwestern Medicine. If you’re managing heart disease, be careful about doing strenuous activity. For example, instead of shoveling snow, consider hiring your neighbor’s kid or a service to do it. “The combination of very cold weather and a lot of heavy snow can put a strain on anybody,” Uren says.

Inflammatory bowel disease (IBD) Ford says it’s hard to predict how the cold can affect IBD. “Most of the inflammation is in the intestines, and that’s part of the core that would be the last part to feel the effects of the cold weather,” he says. “It’s certainly possible that prolonged exposure could make the situation worse, but it would be unlikely to happen from a brisk walk outside.”

Long COVID People with long COVID need to take extra caution in the cold temperatures and snow, says Glatter. According to a review published in July 2021 in the BMJ, lung function and capacity may be reduced for some time after a COVID-19 infection, leading to a higher risk of infection and disease, so Glatter advises those with long COVID to remain at home when temperatures are low to avoid the risk of secondary pneumonia, influenza, and other respiratory viruses. “At the very least, we must advise extra precautions in patients with long COVID; they should make sure to wear a well-fitted N95, KN95, or KF94 mask, particularly in all indoor settings with other people, and in those with poor ventilation,” says Glatter.

Mental health condition “For people with seasonal affective disorder, bipolar disorder, or depression, having to stay inside for long periods of time can be problematic,” says Pedro L. Dago, MD, an assistant professor of psychiatry and behavioral sciences at the Northwestern University Feinberg School of Medicine in Chicago. To manage symptoms, he recommends maintaining a sleep schedule and exercise regimen, and getting as much sunlight as possible. If it’s not possible to go outside, he suggests opening curtains and blinds to let light into your home (and Johns Hopkins Medicine suggests sitting near a window). Be sure to apply sunscreen before exposure to the sun, and choose a product with an appropriate SPF based on the intensity of the sun where you are — yes, even if you’re inside. And don’t let the cold temperatures prevent you from seeking help if you need immediate attention, Dr. Dago says: “There tends to be a decrease in the number of people we see in the emergency department when it gets extremely cold outside, but no one should wait to get the care they need.” Take the precautions already mentioned if you need to venture out, but don’t delay care.

Multiple sclerosis (MS) People with MS may need to take more precautions to maintain mobility in the cold weather than in warmer weather. The cold can exacerbate pain or weakness, per the Multiple Sclerosis Foundation, but the highest risk is loss balance and slips and falls on ice. “You just have to be careful,” Ford says.

Skin conditions Cold, dry winter weather may exacerbate symptoms of eczema and psoriasis, according to Cleveland Clinic and the National Psoriasis Foundation. It’d be a delayed response — you wouldn’t see the effects within minutes of being in the cold — and it should stop as soon as you get into a warm environment. To avoid this, be sure to keep your skin moisturized while you’re indoors. Ford suggests following your normal treatment or medication plan and covering up when you go outside.

Why Preparation Is Key for Surviving the Extreme Cold

One thing to keep in mind: If you’ve lived in an area that has historically had extremely cold temperatures, your body may respond differently to the weather than someone who is from a warmer region. “A lot has to do with what you’re used to and have adapted to,” Ford says. “The body is pretty resilient and has a lot of defense mechanisms.”

Still, manageable steps like dressing in appropriate layers, taking indoor breaks when you’re working outside, and remembering to take it slow on icy roads and sidewalks will help you avoid the pitfalls of winter weather.

“As ER doctors, we’re trying to put ourselves out of business,” Uren says. “We see the bad outcomes associated with extreme weather and so many could be really easily prevented.”