According to WebMD, it's necessary to call 911 when the signs of heat stroke are present. While waiting for the ambulance to arrive, lowering the body temperature is essential.
WebMD states that the following signs of heat stroke should prompt someone to call 911: a fever above 103 degrees; a rapid pulse and reduced sweating; disorientation and unconsciousness; and seizures. While waiting for the ambulance to arrive, cooling the patient down by removing them from the sun is essential. Other first aid measures include spraying him with cool water and applying wet cloths or ice packs to the armpits or groin area. The Mayo Clinic also suggests giving the patient a cool, non-alcoholic drink, if they are able to drink it. However, WebMD highlights that this isn't wise if he is unconscious or vomiting. WebMD also states that it's necessary to keep a patient safe from harm if he has a seizure. If he vomits, it's necessary to place him on this side so his airways remain open.
According to the Mayo Clinic, heat stroke is the most severe heat-related problem after heat exhaustion. It usually occurs when a person exerts himself in a hot environment without adequate hydration. It's more likely to occur in the elderly, young children and obese individuals.