Dry clothing prevents heat loss because it prolongs the time between sweating and cooling. Wet clothing encourages evaporative heat loss.
Light colors reflect heat rays.
Generally, drinking large quantities of low sodium liquids during prolonged exercise in hot, humid weather. Children take longer to acclimatize and have a lower sweating rate and higher corer temp. Body fat acts as insulation and slows down the conduction of heat from the body's core to the shell. Larger, obese people have a smaller surface to body mass ratio for sweat evaporation. Excess body fat also increases the metabolic cost of activity.