Hot and humid conditions aren't just sticky and unpleasant — they can also be dangerous.
In fact, if you don't take precautions in hot weather, you might be affected by
But before heatstroke occurs, you can recognize the warning signs of less severe heat illnesses, and take the proper measures to avoid any
Here's what you should know about keeping your body cool in extreme heat, and what you can do to protect yourself and stay safe.
What is hyperthermia?
Hyperthermia is when your body temperature is abnormally high. It means that your body is overheating, or having trouble regulating your temperature, usually as a result of extreme heat.
Body temperature can reach the following levels:
- Normal body temperature is about 97 to 99°F.
- Hyperthermia is generally above 99.5°F.
- Severe hyperthermia is generally above 104°F and considered life-threatening.
Hyperthermia is different from a fever, as the increase in your body temperature is a response to external conditions like extreme heat, not an internal condition like infection or illness.
Signs and symptoms
Hyperthermia refers to a group of heat-related illnesses, each with different signs and symptoms.
As your body temperature rises, you may experience the following:
Heat rash
Heat rash occurs when sweat gets trapped under your skin as a result of clogged sweat ducts. It commonly appears as small red or pink bumps, and can look like bug bites or pimples.
Typically, you might recognize a heat rash on your body after a day in the sun or heat. There are three different types, all with slightly different symptoms:
Newborn babies are more likely to experience heat rash, as their sweat ducts are small and they are not able to regulate body temperature as well as adults.
However, there's little danger if you or your baby has heat rash — doctors consider it a benign condition and it will usually resolve within hours or days.
Heat cramps
Heat cramps are involuntary muscle spasms that occur from exercise in hot and humid conditions.
When you work out in extreme heat, you're going to sweat more than usual. As a result, your body will lose fluids and electrolytes more quickly, increasing your likelihood for muscle cramps.
If you notice your muscles cramping in the heat, you should stop your exercise immediately and rest in the shade or air conditioning.
Heat exhaustion
Heat exhaustion is slightly more severe, and you may feel symptoms throughout your entire body.
The main symptoms of heat exhaustion are:
- Heavy sweating
- Rapid, weak pulse
- Clammy skin
- Nausea
- Heat cramps
- Lightheadedness
- Shortness of breath
If you continue to expose yourself to heat with these symptoms, it can rapidly develop into heatstroke.
Heatstroke
Heatstroke is the most severe form of heat illness. It's characterized by two main factors: a body temperature above 104 °F and central nervous system dysfunction.
As a result, heatstroke symptoms are very serious, and can include mental confusion, slurred speech, or even a loss of consciousness.
Still, it can sometimes be difficult to tell the difference between heat exhaustion and heatstroke, which is imperative for getting proper treatment. This chart can help you navigate the symptoms of both heat illnesses:
Treatment
If you or someone you know may be having heatstroke, call 911 or get them to the hospital right away. Without immediate medical attention, heatstroke can cause vital organ damage or death.
However, before heatstroke develops, there are a number of treatments you should use to lower your body temperature and cool yourself down.
Escape the heat
If you start to feel any symptoms of heat illness, make sure you get into the shade or somewhere with air conditioning, as staying in the sun will only make your symptoms worse.
Get some rest
Stop any physical activity immediately, and take a break in cooler conditions. If you keep working or exercising, your body will not be able to lower its temperature.
Make sure to hydrate
To treat heat cramps or heat exhaustion, you need to replenish fluids lost through sweating by drinking water. You can also try a sports drink like Gatorade to replace electrolytes and improve hydration.
Put cool water on your skin
One of the quickest ways to lower your body temperature is with cold water. For example, you can take a cool bath or shower, or even spray yourself with a garden hose.
Using wet cloths on your body can also help you cool down, as well as reducing any skin irritation from heat rash.
Wear loose clothing
Tight clothing can trap heat and make it harder for your body to cool itself — light fabrics and loose clothing are always best when it's hot.
Removing any unnecessary clothing can also help your skin breathe and relieve heat rash.
Risk factors
The biggest risk factor for heat illness is strenuous exercise or labor in hot and humid conditions. Pushing your body in extreme heat can increase sweating, loss of fluids, and dehydration — all of which make heat illness more likely.
Anyone can experience heat illness. However, children under four years old and older people over 65 years old are most at risk, as their bodies aren't always able to regulate internal temperature effectively.
Make sure to keep an eye on younger children and the elderly as temperatures heat up, especially if they are without air conditioning while indoors, as this can make it more difficult to stay cool.
Most importantly, you should never leave children, older adults, or animals in a vehicle, as a car can quickly heat up in the sun, leading to dangerous temperatures and a higher risk of heatstroke.
Preparation and prevention
If you're going to be outside in extreme heat, there are a few ways you can prevent heat illness:
- Avoid the hottest part of the day. Try to exercise or work outdoors in the early morning, as temperatures are usually highest in the afternoon, between 3 p.m. and 4:30 p.m. Check your local weather to see hourly temperatures each day.
- Take frequent breaks. Resting can help your body adjust to extreme heat, and doctors recommend taking a 10-minute break for every 20 to 40 minutes of exercise.
- Drink lots of water. In hot conditions, you'll need to stay hydrated before you feel thirsty, so make sure you're routinely drinking water every 15 or 20 minutes.
In addition, you'll want to take a few steps in your home to prepare for a heat wave, or a period of unusually hot weather.
Air conditioning is the best protection from heat while indoors, so check to make sure yours is functioning before you need it.
There are also a few tricks to stay cool without AC, such as blocking sunlight from entering your home with curtains or shades. You can even help cool a room down with fans by placing a bucket of ice in front.
Takeaways
While heat illness can be dangerous, it's easy to avoid, as long as you take preventive measures to stay safe in extreme heat.
When it's hot out, you should pay extra attention to those at a higher risk of heat illness — such as younger children, old people who live alone or without AC, and anyone who may be working outside or exercising in extreme heat.
And if you do recognize the symptoms of heat illness, make sure you know how to cool someone down and lower body temperature before it affects their health.
This article was medically reviewed by Jason R. McKnight, MD, MS, a family medicine physician and clinical assistant professor at Texas A&M College of Medicine.