Running in sun, heat, and humidity requires that you take special precautions. Minimizing fluid loss and heat gain is essential. Some tips to remember:
Drink water whenever possible. Water is the vital ingredient in the prevention of heat injury. Thirst is not a reliable indicator to warn a runner of fluid loss. Your body loses a considerable amount of fluid before you feel thirsty.
Avoid caffeinated and alcoholic beverages which have a diuretic effect.
Wear white clothing to reflect the sun’s rays. Avoid dark clothing which absorbs heat.
Run during the coolest part of the day.
Choose a shady course.
Run where you have access to water.
Splash yourself with water to aid in cooling your body.
Remove wet clothing which hampers evaporation.
Be aware that increased humidity blocks body cooling via evaporation of sweat. Avoid running when relative humidity exceeds 90%.
Avoid running long distances alone.
Know the warning signals of heat-related problems:
Do not try to run through heat cramps: stop, rest, drink water;
Signs of heat exhaustion are faintness, weakness, and mental confusion: if symptoms develop, stop, find shade, drink water;
Signs of heatstroke are decreased sweating and hot, dry skin: stop all activity and find a means of cooling your body as rapidly as possible, remove clothing and rub body with ice and alcohol, seek medical treatment.
Consider another form of exercise when adverse weather conditions make running dangerous.