What is heat stroke?
Heat stroke is defined as having a body temperature of greater than 40.6 degrees Celcius (105.1 degrees F). It's caused by the inability of the body to self-regulate it's core temperature due to heat and humidity. The body cannot get rid of all this excess heat - which it would normally do by sweating. This is why excessive humidity is a strong correlating factor. Predisposition to heat stroke can happen with the use of caffeine, stimulants, medications and alcohol - they all cause dehydration and inhibit cooling. Heat stroke also happens with young, fit people under exertion in the heat - think army recruits or football players.
Symptoms of heat stroke
Heat stroke symptoms include confusion and lack of sweating - confusion because your brain heats up and it starts behaving strangely, and lack of sweating because your body can't perspire enough to keep your body temperature down, so it stops altogether. Then things cascade rapidly.
Prevention
Prevention of heat stroke is sometimes easier said than done. Primarily, avoid dehydration and overheating. Wear light colored clothing that will allow your perspiration to evaporate (and cool your body). Wide brimmed, light colored, vented hats don't allow direct sunlight to hit your head and neck, but will allow sweat from your head to evaporate. Remember that as humidity goes up, your body has a harder time regulating your internal heat, so it needs all the help it can get. Make sure that the clothing you are wearing both blocks harmful UV from the sun, and doesn't absorb the heat (so, light colored), but also that it allows perspiration to evaporate - chose fabrics like cotton over artificial, non-breathing, plastics.
Avoiding strenuous exercise during daylight hours is another practical tip - heat exhaustion is common among athletes. Stay out of enclosed spaces like cars - they can reach up to 200 degrees (F) very quickly in the right conditions. Children and pets are especially prone to quickly succumbing to heat stroke (and death) in cars baking in the warm sunlight. We hear about these instances in the news every summer. Dogs and cats cannot sweat through their skin (fur), so they are much more apt to succumb to heat stroke than people. Leave your pets at home!
It's also very important to remain hydrated. Thirst is not a good measure of hydration. Rather, the color of your urine is ... make sure it remains "straw colored" or even clear. Drink often, and maintain that color! There's come controversy whether it's better to drink sports drinks or water, as when you sweat you lose valuable sodium (which sports drinks replace). Low sodium can cause heart attacks, so maybe 50/50 is the right answer for a long day in the sun.
Treatment
The treatment for heat stroke is to quickly lower the body temperature and resuscitate (if they're not breathing) using CPR. Rapid lowering involves moving the person indoors (or into the shade if indoors is unavailable). Remove their clothing to promote "passive" cooling ... a fan or air conditioner can help. Active cooling can involve a cool (not cold) bath or a hypothermia vest. Applying cool towels to the head, neck, groin and torso can also help.
Re-hydration is very important too. If the patient can drink - get them water immediately. If they're unconscious, you'll have to have an IV started (bottom line - get emergency help). Cooling and re-hydrating a body can get complicated (you don't want to prevent sweating or promote heating). But those first few minutes can save a life - do what you can before the emergency team shows up!
