But anyone exposed to enough heat can develop heatstroke, heat exhaustion or other heat-related illnesses. Heatstroke, the most serious of these illnesses, occurs when the body loses the ability to cool itself.
Victims can go from apparently normal to extremely ill in a matter of minutes.
Persons suffering from heatstroke need immediate medical attention. Heat exhaustion is a milder illness that may take several days of high temperatures to develop. It occurs when the water and salts lost through perspiration are not adequately replaced. Victims may have pale, clammy skin and be sweating profusely. They may feel tired and weak, dizzy, have a headache and sometimes cramps, but their body temperature is close to normal.