Sweating is the body’s way of avoiding overheating. However in warm, humid conditions this mechanism is less effective. Other factors can also increase the risk of overheating, for example a person’s health and fitness. People who are obese or who have thyroid problems, or a disorder which affects their production of sweat, or who have previously suffered from overheating are all at greater risk. Age is also a factor: babies and the elderly cannot control their own body temperatures as effectively.
To prepare your body for being in a hot climate you can try to get used to heat before departure for example by going to a sauna or spending time in the sun. The body then tends to adjust to the higher temperatures. You can enhance this effect by playing sport or doing exercise in a heated sports hall. In this way you can judge which conditions you feel comfortable in and after eight to ten days your body should have sufficiently adapted to perform well in the country of destination. It will require about the same length of time to readjust on your return.
Once at your destination, you can take additional precautions to prevent overheating, first of all by drinking a lot especially cold drinks. Water (bottled, if need be) has the quickest effect and contains no fat or sugars. Be sure to get adequate rest, avoid the sun during the hottest hours of the day and use sunscreen (minimum SPF 30). Lightweight, loose-fitting clothing also helps, as does protecting your head with a cap or hat.
Sun stroke and heat stroke are both forms of/consequences of hyperthermia (overheating). It is important to be able to recognise the symptoms of each and to know what you should then do.
Fainting in a hot environment can be the first sign of overheating. At this stage the body temperature is still normal. Another possible sign is cramping of the muscles. A rash may also appear. When sweat glands are clogged and slightly inflamed due to the heat this can cause redness, itching and sometimes blisters. Water retention in the legs is another known sign of overheating. This should resolve itself if the person sits with their legs raised. If any of these symptoms are experienced, the simple steps set out above should be enough to bring relief. However, in cases of serious overheating, medical attention is almost always necessary.
Hyperthermia is where the body has noticeable difficulty in dealing with heat. The body temperature is usually normal, and never above 41°C. The sufferer still perspires and remains conscious. However, there is often dehydration and sometimes muscle spasms. In addition, people suffering from hyperthermia often feel tired, sick, weak and dizzy. The condition improves as soon as the person is no longer exposed to heat and if he or she takes on extra fluids. If the body temperature is above 40°C efforts should be made to cool the person down. Heat should be avoided for the following 24 to 48 hours to prevent symptoms recurring.
Hyperthermia can develop into heatstroke or sunstroke. Three things happen:
Someone with these symptoms needs urgent medical attention. Heatstroke is classically associated with the elderly but young people who expose themselves to heat can also suffer from it. Active cooling is required in order to lower the body temperature as quickly as possible. This can be done immediately by applying ice packs to the armpits and groin, but the sufferer needs to be taken to a hospital as soon as possible.