Running in hot weather can have adverse affects to the body if not treated properly and with precaution. Heat rises the temperature of the body and can cause dehydration, dizziness, disorientation, heat cramps or heat stroke. The most important point to remember is to take it easy when running in hot conditions. Even the most well conditioned athletes have to be careful, although the fitter a person is usually the better that person can cope with running in hot weather. If you are not used to running, the heat, or both it is well advised to start cautiously and build gradually. This usually means initially decreasing the pace and distance of the runs. However, by properly adjusting to running in the heat it is possible to run the same distances and frequencies of cooler conditions provided correct precautions are taken with regards to drinking, clothing and the timing of the runs.
The best time of the day to run during periods of extreme hot weather is early in the morning before the sun rises, or late at night after the sun has disappeared. If humidity is high, it is better to run in the morning since humidity reaches it's maximum during the evening. However, if it is unavoidable to run at these times run in shaded areas such as trails. Avoid running on long open roads where the dark surfaces of the roads absorb the heat and causes hotter conditions. Alternatively, run at an indoor track or on a treadmill in a place that is well air-conditioned. If such facilities are unavailable run in areas where you know there is water drinking sources, such as water fountain, at regular intervals. Also, run small circuits close to where you start. Therefore, if you start to feel the affects of the heat you can stop before causing serious damage to your health.
When running in hot weather it is advisable to wear lightweight and light-coloured outfits. Even though maximum skin surface should be showed to help the evaporation of sweat, a light-coloured singlet can act as a radiation shield since the skin is not a good reflector of heat. The lightest and most practical type of clothing for this is any garment that is made out of the material called "Coolmax". Coolmax is a lightweight material that wicks away sweat on the outside of the material. Light colours are better in hot weather since they reflect heat, while dark colours absorb heat. A pair of shorts and a singlet is adequate and advisable clothing in hot weather.
Fluids, especially water, are paramount to hot weather running. All runners running in heat should hydrate themselves generously before the start of a run. Running in heat causes a fluid deficit, more so for the heavier built and elite runner. The longer the distance runs the more fluid that is lost. During all runs in hot weather the runner should attempt to drink. Likewise, it is important to drink after the run to keep the body hydrated. It is recommended that the average person should drink at least 8oz of water a day for every 20lbs he or she weighs. Therefore, someone weighs 140lbs needs to drink 56oz of water per day. In conditions of extreme heat, this amount needs to be higher since the body looses more fluids.
