Heat stroke is an abnormally elevated body temperature with accompanying physical and neurological symptoms. Unlike heat exhaustion heat stroke is a true medical emergency that can be fatal if not properly and promptly treated. Heat exhaustion is a milder form of heat-related illness that can develop after several days of exposure to high temperatures and inadequate or unbalanced replacement of fluids. Symptoms of heat exhaustion include: Nausea, vomiting, fatigue, weakness, headache, heavy sweating, paleness, fainting, muscle cramps/aches, and dizziness. The skin may be cool and moist. The victim’s pulse rate will be fast and weak, and breathing will be fast and shallow. If heat exhaustion is untreated, it may progress to heat stroke, which is a medical emergency. Seek medical attention and call 911 immediately if: symptoms are severe, or the victim has heart problems or high blood pressure. Otherwise, help the victim to cool off, and seek medical attention if symptoms worsen or last longer than 1 hour. Heat exhaustion treatment: cooling measures that may be effective include: cool, non-alcoholic beverages; rest; cool shower, bath, or sponge bath; an air-conditioned environment. Different people may have different symptoms and signs of heat stroke. But common symptoms and signs of heat stroke include: High body temperature; the absence of sweating, with hot red or flushed dry skin; rapid pulse; difficulty breathing; strange behavior; confusion; agitation; disorientation; seizure and coma. How do you treat a heat stroke victim? Victims of heat stroke must receive immediate treatment to avoid permanent organ damage. First and foremost, cool the victim. •Get the victim to a shady area, remove clothing, apply cool or lukewarm water to the skin (for example you may spray the victim with cool water from a garden hose), fan the victim to promote sweating and evaporation, and place ice packs under armpits and groins. •Monitor body temperature with a thermometer and continue cooling efforts until the body temperature drops to 101-102°F (38.3-38.8°C). •Always notify emergency services (911) immediately. If their arrival is delayed, they can give you further instructions for treatment of the victim. Source: http://www.medicinenet.com