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Weather Home UK World Sports Coast and Sea Climate Change Features Understanding Weather Sport and Leisure Health and Culture History, Literature & Religion Science and Nature Coast and Sea Weatherwise About BBC Weather Site FAQ About the BBC	Heat Effects

		People who live in countries with a hot climate generally stay out of the sun when it is at its peak to prevent heat illnesses.	Key Points Humans sweat in hot temperatures to cool down. Salt is essential to the body as it helps the cell tissues retain water. Heat rashes reduce the body's ability to sweat making heat less tolerable. People do gradually acclimatise to hotter climates. Also in BBC Weather Frostbite bbc.co.uk Links BBC Health Disclaimer The BBC is not responsible for the content of external websites.

	Obviously there is the risk of sunburn, but there are many more heat disorders that can strike. In high temperatures humans sweat to cool down. Sweat evaporates from the skin removing excess heat. Logically you sweat more in hotter climates, and the body tries to adapt to the climate by adjusting the amount of salt in the perspiration. Salt is essential to the body as it helps the cell tissues to retain water. The body must retain the necessary salt levels in the cells, whist cooling the body to 37°C (98.6°F). If the body loses too much salt or water it can become life-threatening. Humidity can significantly add to the 'apparent' temperature... Humidity can significantly add to the 'apparent' temperature by reducing the body's ability to cool itself down. At 24°C, (75°F), and a humidity of over 50 percent the body experiences a temperature greater than that of the actual thermometer reading, increasing the threat of heat stress. Excessive sweating can lead to painful muscle spasms called heat cramps, or to heat exhaustion, which has many symptoms including excessive thirst, dizziness and nausea. Both can be treated by drinking water and resting in a cool place, but heat stroke requires urgent medical attention. The body's thermostat stops working, so sweating is significantly reduced, or can stop altogether, and the body's temperature becomes very hot (sometimes over 40°C, 104°F). Heat stroke is less common in the British Isles... Heat stroke is less common in the British Isles than in other countries nearer the Tropics, as our Summers are relatively mild. Heat rashes are far more common. This is not just an itchy rash, but it also reduces the body's ability to sweat making heat less tolerable. People do gradually acclimatise to hotter climates. The body's perceived exertion and heart rate all adapt with time, but some insects and animals can adapt much better. Studies on locusts from cool climates revealed that they have trouble flying, or even die, if released into hot deserts unless they have been previously exposed to the heat for a short period. Brief exposure to high temperatures has a lasting effect on their nervous system and it is these changes that could enable animals to fly in very hot environments.

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Heat Effects