Summer is "around the corner" and it is time that we all got ready for the warm weather. Since none of you "Birddogers" have contacted me and requested a subject, you now have to "suffer" through the discussion on HEAT INJURIES. We have all heard it before, but "repetition is the hallmark of adult education." For those of us who have gone to Keokuk, we know that Iowa is HOT in July. So, let’s see how are bodies can combat the heat and what can happen when the heat is too much for us.

Our bodies are wonderful "steady state" machines. All of the systems of the body work together to keep a rather constant core temperature. How do we combat significant increases in heat? Sweating is the most effective natural way to combat heat. As long as sweating continues, providing salt and water are replaced, man and woman can withstand extremely high temperatures. More than three liters of sweat can be lost per day. Another means of losing body heat is the dilatation of peripheral blood vessels. This means that the vessels in the skin get bigger. More blood can flow near the surface and give of heat (like a radiator). Obviously, this isn’t as effective as sweating. Internally, there is decrease in the total circulating blood volume, decrease to the blood flow to the kidneys and increase to the antidiuretic (ADH) substance in the urine.

Heat Cramps

The first heat injury and the least serious is heat cramps. This is usually painful spasm of the muscles following strenuous exercise. This can even be experienced by people who are in good physical condition. The theory is that these cramps are caused by the depletion of electrolytes (such as sodium) during sweating. The cramps do not have to occur during hot weather. Everyone will recover from this with replenishment of the water and electrolytes.

Heat Exhaustion

The most common serious heat injury (and a very serious medical problem) is heat exhaustion. Heat exhaustion occurs when our body’s mechanisms cannot cope with and remove our internal heat. Symptoms can include weakness, dizziness, fatigue and fainting. The onset can be sudden and there can be collapse without warning. Warning signs are present! The person stops sweating and may look ashen-gray. Instead of sweating the skin is cold and clammy. The pupils may be dilated. The blood can be very thick and concentrated (They have sweat so much that there is no more ability to sweat.). The body temperature is normal. Treatment has to be immediate! Cool the patient and get him/her fluids ASAP! IV fluids would be preferred. If heat exhaustion isn’t turned around the patient could take the last step………..

Heat Stroke

Heat stoke is a very serious medical problem. Many of these patients will die. People with predisposing medical problems are at risk. This is obvious. Some of these people’s body systems may not be working at maximum efficiency at the beginning. High humidity is often a problem (you can’t give of as much sweat if the air is already saturated). The same symptoms as heat exhaustion are seen. There may also be delirium. Still, the absence of sweating is "the bad sign." The body temperature is very high (this is the way that you can tell that heat exhaustion has developed into heat stroke). Body temperatures may be in the region of 106 to 110 degrees. The skin is very hot and dry. There is no sweating. The blood pressure and pulse are elevated. I could now go into the ugly details of how all of the body systems and fail, but that is beyond the scope of necessary knowledge. Time is very important. Cool the patient! This means an ice tub bath! Give the patient fluids! IV’s are a must! This patient will die if his temperature is not controlled. He should be taken to a hospital immediately. But, once again, the first priority is to decrease the body temperature.

Managing Heat

The basics are simple and we should all follow them, wherever we go (even Keokuk).

1. Hydrate, hydrate, hydrate. When you are first thirsty, you are already two quarts of fluid low.
2. Keep covered. Bare skin soaks up the heat. Ventilated clothes are the best for cooling.
3. Know the symptoms of heat injuries (they are all discussed above).
4. Remember that you also loose salt when you sweat.
5. Alcohol decreases your heat tolerance. Your fluids are lost in your urine and you don’t have that fluid to use as sweat (sorry about that fact).
6. Sweating is good. If you stop, you are in trouble.

REX 79

Attached is the way that you cooled of in Vietnam. You take the Birddog up to 1000 feet and fly with all of the widow open.

Fly Safe! REX 79

Written for Birddog owners by Dr. Steve Frushour, IBDA Aero-Medical Officer