The body works hard in all weather conditions to maintain a normal temperature of 98.6 degrees. When temperatures are extreme, whether it’s a scorching summer day or a freezing winter morning, your body may find it difficult to maintain this ideal temperature.
“Even when we are at rest, the human body generates a lot of heat energy,” says Eric Buete, MD, medical director of AFC Urgent Care in Sarasota, Florida. When the temperature is cool, your body will expel this heat through radiation. “The heat simply radiates from the body to the surrounding air,” Dr. Buete explains.
When it’s hot outside, your body sweats to keep cool. Perspiration rises to the skin’s surface. According to Houston Methodist, as it evaporates, you begin to feel cooler. When it’s humid outside, the perspiration on your skin’s surface has a harder time evaporating because the air is already saturated with moisture. That’s why people often say it’s the humidity, not the heat, that makes being outside on a hot day unbearable — even though both play a role in your body overheating.
In some cases, sweating may occur without any external trigger.
Knowing whether you’re at a higher-than-usual risk of heat-related illness, as well as what’s causing your symptoms, can help you decide what steps to take.
This collection of quick facts is a good place to start.
1. Extreme heat is hazardous — and sometimes fatal.

According to the Centers for Disease Control and Prevention, approximately 618 Americans die each year as a result of extreme heat (CDC). Seniors, young children, and people with mental illnesses and chronic conditions such as heart disease are the most vulnerable, according to the CDC, with athletes, outdoor workers, and people from the Black, Indigenous, and People of Color (BIPOC) communities being especially vulnerable.
2. Men sweat a lot more than women do.
While women have more sweat glands than men, men’s sweat glands are more active, causing males to sweat more than women, according to the US National Library of Medicine. According to Buete, the more you sweat, the easier it is to become dehydrated, which can lead to various health problems.
3. Your body has up to 4 million sweat glands.
According to the International Hyperhidrosis Society, this is true. Eccrine and apocrine sweat glands are the two types of sweat glands. Fluids are produced by both. The hypothalamus, a part of the brain, regulates your body temperature by controlling perspiration output and blood supply to the skin. Sweat odor is produced by apocrine glands in the armpits and vaginal region; when sweat from these glands comes into touch with microorganisms on the skin, it produces an odor.
4. When your body overheats, you get heat exhaustion.
The CDC lists dizziness, nausea, vomiting, weariness, intense sweating, and headache as warning signs of heat exhaustion. Heat exhaustion can be treated by moving to a cool environment, drinking plenty of water, and soaking in a cool bath or applying cool compresses.
5. Heatstroke, a life-threatening condition, can result from being overheated.

According to the American Academy of Family Physicians, heatstroke occurs when your body temperature hits 104 degrees and your body loses its ability to regulate temperature on its own (AAFP). Muscle cramping, a racing heart, vomiting, flushed skin, headache, mental confusion, and seizures are all symptoms of heatstroke, according to the CDC. If you notice someone experiencing these symptoms, call 911. Heatstroke should be treated similarly to heat exhaustion: the person should be transported to a cooler location and given a cool water bath or compresses.
6. Staying hydrated can help protect you from heatstroke.
Buete advises, “Drink before you’re thirsty.” Caffeine and alcohol should be avoided in excessive heat, according to the American Academy of Family Physicians. Avoid exercising outdoors during the hottest portion of the day, which is usually between 11 a.m. and 6 p.m., by wearing loose clothes that allows air to circulate about you. Instead, time your workout to be as close to sunrise or sunset as possible.
7. Heat-Related Illnesses are especially dangerous for infants and small children.
This is true for various reasons, according to Buete. They can’t regulate their environment (for example, if kids’re left in a hot room); they have a fast metabolic rate, which means their bodies are continually producing heat; and they can’t perspire as much as adults, according to Buete. Even if the windows are open, never leave a youngster in a parked automobile.
8. Adults in some groups are also at a higher risk of becoming ill as a result of extreme heat.
According to Buete, this includes morbidly obese persons, the elderly, and people who are immobile. According to Matthew Corcoran, MD, CDCES, medical director of the Joslin Diabetes Center affiliate at Atlanticare in Egg Harbor Township, New Jersey, people with diabetes can be heat sensitive as well. Dr. Corcoran warns that if you have diabetes and become dehydrated due to the heat, it can alter your blood sugar levels. Keep insulin and other diabetes prescriptions out of the heat, as they can be ruined by high temperatures, he says. When people with multiple sclerosis get too hot, their symptoms may increase. When a person’s body temperature rises, the central nervous system struggles to function effectively.
9. Some medications can make you more susceptible to heat stroke.
According to the AAFP, these include allergy and antihistamine medications, blood pressure and heart medications, diuretics, laxatives, antidepressants, and seizure treatments. If you’re taking any of them, talk to your doctor about the precautions you should take.
10. Excessive Sweating is caused by a health condition that affects about 3% of the population.

According to the Center for Sweat Disorders at Johns Hopkins Medicine, hyperhidrosis is a disorder characterized by overactive sweat glands that induce excessive sweating. This illness can be hereditary or caused by other illnesses or treatments, and it can strike without being triggered by heat. Oral and topical medicines, Botox injections, and a technique that utilizes electricity to switch off the sweat glands are all options for treating hyperhidrosis. If these treatments do not work, you may want to talk to your doctor about surgical options.