What is heat stroke?
Heat stroke is a potentially serious medical condition where a person has become so hot that their body can’t cool down and their temperature gets dangerously high.
Sunstroke is a form of heat stroke caused by being exposed to harsh sunlight.
Although it normally affects people during a heat wave it can also happen if you’re not drinking enough water and are doing very strenuous physical exercise.
Severe heat stroke is life threatening and is a medical emergency. It happens when a person’s body temperature becomes dangerously high and they are unable to cool down.
Risk factors for heat stroke
The risk increases once the temperature reaches 26C (close to 79°F) or more so pay attention to the weather forecast and remember that it will be hotter in the sun than in the shade.
Other risk factors include:
- Age – adults over 75, infants and children up to the age of 4, adjust to heat more slowly
- Chronic illness – including heart, lung or kidney disease
- Diabetes – people with diabetes may be especially likely to underestimate their risk during heat waves
- Mental illness.
- Physically strenuous exercise like that done by athletes, manual workers and those in the military.
- Being underweight or overweight.
- Having high blood pressure.
- Having sunburn or any condition that can cause fever.
- Wearing tight restrictive clothes.
- Being somewhere with little breeze or ventilation.
- Where you live – if you live in a built-up area then during a prolonged heat wave the roads and buildings will store the daytime heat and only gradually release it at night, resulting in higher night-time temperatures.
Symptoms of heat stroke
The hallmark symptom of heat stroke is a core body temperature above 40C (104° F). However, fainting may be the first sign.
Other symptoms include:
- Throbbing headache
- Feeling and being sick
- Muscle cramps
- Intense thirst
- Darker wee than normal
- Rapid heartbeat
These can develop quickly, within minutes, or over several hours or days.
Diagnosis of heat stroke
Heat stroke is diagnosed by observing the signs and symptoms of someone who has been exposed to extreme temperatures.
Treatment for heat stroke
Treatment involves lowering the person’s core temperature.
If you think someone is having seizures, is confused or is unconscious because of heat stroke then this is a medical emergency and you need to call an ambulance (dial 102). Whilst waiting for help try to lower their temperature by getting them to a cool, shady or air-conditioned area and removing any unnecessary clothes.
You could also:
Wet their skin and fan air over them.
Apply ice packs to their neck, back, armpits and groin. These are areas rich with blood vessels close to the skin and cooling them may reduce body temperature.
Get them to drink water, fruit juice or a sports rehydration drink providing they are conscious and able to swallow.