WHAT IS HEAT STROKE: The body controls heat through the hypothalamus, an area of the brain that secretes chemicals to control the body's metabolism. The amount of heat the body produces is balanced naturally with the amount of heat lost through sweating. Normally, sweat evaporates from the skin. But if someone is exposed to high heat and humidity, the air is already saturated with moisture and the sweat will not dry quickly enough to cool the body. The body loses water content, along with essential body salts. If the body's core temperature gets high enough, the brain will overheat, causing the person to become disoriented or aggressive; he or she may even begin to hallucinate.
WHAT TO DO: Heat stroke can quickly lead to disability or death, so it's critical to begin cooling efforts immediately until medical help arrives. For example, remove the victim's clothing and apply cool water to skin, then fan the victim to induce sweating. You can also apply ice packs to the groin and armpits; immerse the victim in a tub of cold water or cold shower; or spray the victim with cool water from a garden hose.
CONCUSSION ALSO A DANGER: More than 750,000 mild traumatic brain injuries occur each year in the U.S., many during a game. If the injury is misdiagnosed, and the player goes back on the field, a second impact injury shortly after the first can lead to permanent brain damage or possibly death. But in the heat of a sports competition, such injuries can be missed. Symptoms include temporary unconsciousness, headache and sometimes a loss of memory surrounding the time of the injury. Vomiting and nausea are also common reactions.