Many parts of the southern hemisphere, particularly Southern Africa are currently experiencing unseasonably hot weather conditions. This has implications for all people exercising and playing sport in such conditions, but even more at risk for heat related illnesses are children whose physiological and structural differences impact on their ability to respond to environmental heat.
Heat stress can occur during normal weather conditions if the exercise intensity is very high. However, in hot and humid weather the risk increases either because people cannot produce enough sweat for cooling or the high humidity prevents adequate evaporation of sweat. Children sweat less and are therefore less able to get rid of heat in warm to hot weather. They will look flushed and feel hotter and more stressed than adults. Overweight children are even more disadvantaged exercising in hot weather.
Heat related illnesses are complex and individual tolerance varies widely. Children are good at “listening to their bodies” and regulating their physical activity. Therefore, children should be allowed to exercise at their preferred level of intensity particularly when the risk of heat illness increases. If they appear distressed or complain of feeling unwell, they should stop exercising and be removed from the sports field. Thereafter they should lie in a cool place, remove excess clothing and have their skin cooled by application of a cold cloth and/or fanning. Also make sure they are adequately hydrated. As the risk of heat stress increases with increasing exercising intensity, different types of exercise/sports can affect the potential for heat illness. Endurance running has a higher risk of heat illness than tennis and cricket.
How to minimise the risk of heat illness?
- Make sure your child modifies his/her exercise intensity when the weather gets too hot. When the ambient temperature exceeds 36 degrees Celsius, sport should be postponed to a cooler part of the day or cancelled.
- If your child has not exercised for a while in warm weather then their intensity should be lower until they acclimatise to the warmer weather. This would be particularly relevant after winter or at the beginning of a season or new school year when children may not have been doing much high intensity training and may be lacking fitness.
- Increase levels of hydration before, during and after exercise and matches. Water is best.
- Increase rest periods and in team situations allow for rotation of players. Rest should be in the shade where possible and cooling aids such as ice packs provided.
- Clothing should be light coloured, loose fitting, natural fibres or composite fabrics and allow for adequate ventilation.
- Wide brimmed hats are preferable to caps and adequate sunscreen.
Make sure your school or club has a policy pertaining to exercise in the heat and that the coaches understand the implications thereof, how to adapt training in hot conditions and how to manage a potential heat related illness.