How to

20 February 2017

Heatstroke: Causes, Symptoms and Treatment

Img: Jeff Turner 
Hot temperatures in the summer can be great for getting your summer tan, however potentially dangerous for your health. Heatstroke is a serious condition which is caused by extremely high body temperature, either caused by prolonged exposure to direct sunlight in hot climates (some call this Sun Stroke), or by persistent strenuous exercise causing the body to overheat.

Heat Exhaustion vs. Heatstroke:

Heat exhaustion is the less serious of the two, which if not treated, can lead to the less common, but more dangerous heatstroke.

It occurs when the body’s salt and water levels are decreased, and body temperature is increased to a level which causes a general unwell feeling in the individual. Of the two, it’s easier to control and treat, by hydrating and cooling the body.

Heatstroke however is when the body’s temperature is dangerously high and no longer able to cool itself.  The NHS website lists the signs and symptoms of heatstroke as:
  • tiredness and weakness
  • feeling faint or dizzy
  • a decrease in blood pressure
  • a headache
  • muscle cramps
  • feeling and being sick
  • heavy sweating
  • intense thirst
  • a fast pulse
  • urinating less often and having much darker urine than usual
“If left untreated, more severe symptoms of heatstroke can develop, including confusion, disorientation, seizures (fits) and a loss of consciousness.”


The risk of heatstroke is increased as temperatures reach 26°C (about 79°F), so in the UK’s summer months or if you’re lucky enough to holiday in a warm country, it’s important to keep an eye on the weather forecast, your hydration and overall health. Heatstroke strikes when the core body temperature reaches 40°C (104°C).

Risk is also increased in the elderly, children under the age of 4, those with diabetes, high blood pressure or chronic illnesses, or those under or overweight, as reported on the WebMD Boots information page on the condition.

Heatstroke puts strain on the brain, heart, lungs, liver and kidney, and if inefficiently treated, can be life threatening. The UK sees around 2,000 deaths due to heat-related illnesses per year, and this figure is expected to rise in the coming years, predicted to rise by around 257% by the 2050s, as reported by Patient UK.

If symptoms of heat exhaustion or heatstroke occur, the NHS advises how to help the individual;
  • get them to lie down in a cool place – somewhere shaded with air con
  • remove any unnecessary clothing – expose as much skin to the cool air as possible
  • cool their skin – using a wet sponge/flannel, or placing cool packs around the neck, armpits, back and groin
  • fan their skin while it’s moist – to evaporate the water on the skin
  • get them to drink fluid – ideally water, fruit juice or a rehydration drinks such as a sports drink

The recovery for heat exhaustion should be around 30 minutes. If symptoms persist, or the individual falls unconscious and experiences seizures, it’s advised to call 999 and place the individual in the recovery position while still using the above techniques to cool them down.

Preventing heat exhaustion or heat stroke is simply being aware of your clothing, hydration, and avoiding direct sun exposure in the hottest period of the day (11am-3pm). Also take note of your environment, e.g. using air con while exercising and, closing blinds or curtains in summer months.

Keep warm, but not too warm; enjoy the hot weather safely. For more information, visit the NHS website. Or, for advice concerning contrasting conditions and weather, have a read of our Survival articles.



Laura Sewell

An aspiring journalist, Laura is our content writer intern.  Pop-punk gig-goer and drag queen enthusiast, Laura is working her way into the industry, with an English A -Level and love of writing about anything and everything in tow.