Doctorsdefine hyperthermia as a body temperature that is over 101 degreesFahrenheit (equal to 38.3 degreesCelsius).[1] This is higher than the normal healthyhuman body temperature, which is normally around 98.6 degrees Fahrenheit (37 degrees Celsius). When a person gets hyperthermia, they can haveheat-related injuries, where the high body temperature hurts the body.
There are three forms of heat-related injuries caused by hyperthermia:heat cramps (the least serious),heat exhaustion, andheat stroke (the most serious).
All types of hyperthermia can be caused by the same things. Some common causes are:[2]
Weather: Weather that is very hot, sunny, andhumid
Activity: Exercising or working a lot, especially if it is hot out
Older people andinfants can get hyperthermia even if they are resting inside, if the weather outside is hot andhumid, and they are not getting enough cool air. This can happen because very old and very young people have trouble controlling their body temperatures.
Illegal drugs, especiallyecstasy andamphetamines, can make the body's temperature get very hot, very quickly[3]
Other things that make a person more likely to get hyperthermia, especially if they are exercising or working, include:[2]
Clothing: Wearing dark clothing, hats or helmets, or padded clothing (like football pads)
Body weight: Having more bodyfat makes it harder for the body to cool down
Dehydration (not having enoughfluids in the body): This makes it harder for the body to cool itself down bysweating
Fever: Because the body's temperature is already higher than normal
Heat stroke happens when a person gets so hot that their body cannot do anything to bring their temperature down. The body has tried every strategy it has to cool itself down. But the body is so hot that none of those strategies work any more. This causes the body temperature to rise very quickly. The body gets so hot inside that itstissues, especially thebrain, get damaged. Usually, people with heat stroke have a body temperature of 104 degrees Fahrenheit or higher. The brain cannot survive for long at these temperatures. Heat stroke can very quickly cause damage to the brain,heart,kidneys, and muscles.[1]
A British soldier in the Middle East has heat stroke and is being cooled with water spray (1943)
People with heat stroke always need emergency medical treatment as soon as possible. If a person might have heat stroke,9-1-1 or anotheremergency telephone number should be called right away. Theemergency medical dispatcher can explain what to do to help the person until anambulance gets there.
Once the person with heat stroke gets to an ambulance or ahospital, treatments for heat stroke may include:[4]
Cooling the person down as fast as possible. Ways to do this include:
Taking the person's clothes off
Covering the person with wet towels
Turning up the air conditioning or turning on a fan, if possible
Putting ice packs in the person'sarmpits, on the back of their neck, and in theirgroin
Putting the person into an ice bath
Giving cold intravenous fluids, both to help cool the person down and to help with dehydration
Givingbenzodiazepines to stop shivering from being cooled down so quickly (shivering makes the body even warmer)
Theprognosis for people with heat stroke depends on how high their body temperature got, how quickly their body temperature increased, and how quickly they got treatment.
Up to 80% of people who do not get treatment for heat stroke right away die.[4] But cooling people with heat stroke down right away, and getting them treatment very quickly, can change this so that only 10% die.[4] But some people who survive have brain damage or other health problems caused by their heat stroke.
