"Managing Heat"

by Jerry T. Sun

As we learned in the MSF course, riding a motorcycle involves managing risk. The same may be said for heat. We don't beat the heat, instead we learn to manage the heat. The National Weather Service has defined four categories of heat. The first is when the outside temperature is 80 - 90 degrees. Exercise caution during these days. Heat fa-tigue is possible with prolonged exposure and/or activity. The second is classified as dangerous when the temperature reaches 90 - 105. Heat cramps, heat exhaustion and heatstroke are possible with prolonged exposure and/or physical activity. Extreme danger is classified at temperatures in the 105 - 130 degree range. Heat cramps, heat exhaustion and/or headaches are possible in short activities, with heatstroke possible with pro-longed exposure and/or physical activity. Above 130 is considered life threatening. At these temperatures heatstroke is very possible with short exposure and/or activity.

To determine just how hot it is, a heat index was developed. This tells us how hot it feels (no breeze present, in a shaded area). It takes into account the humidity as well as the temperature. For instance a 96-degree day with humidity of 45% feels like it is 106 outside. Enough of a difference to go from a dangerous day; to a day classified as extreme danger. If you are out in the direct sunlight you can add up to 15 degrees to the figures on the charts. Along with the outside temperature and humidity we also have to deal with other sources of heat. Extra heat will come from our motorcycles, the pave-ment, and even from our own bodies. Knowing the various sources of heat means we can start to learn how to manage the heat.

Our bodies do a wonderful job managing heat. As our internal temperature in-creases from 98.6 the body responds by increasing our heart rate; the blood vessels ex-pand because more blood flows through them and the capillaries in our skin begin to fill from the increased blood flow. With the blood closer to the surface of the skin (this is why most people turn red with moderate activity on a hot day), it transfers our internal heat to the outside air. But as the outside temperature rises, we are no longer able to transfer our internal heat as easily to the outside air. Our brain, sensing that increasing the heart rate is not enough by itself, signals our bodies to produce sweat (which contains electrolytes). This sweating (with evaporation) is now the principle means of cooling ourselves. With high humidity the evaporation is slowed substantially, but we continue to sweat. It is through this process that we lose electrolytes. The first step in managing heat is to give our bodies an easier way to get rid of the excess heat. There are three ways to accomplish this. Reduce the amount of external heat, increase the cooling effect and minimize internal heat.

By watching what we eat and drink on the road, we can help minimize some of the internal heat. Foods high in protein should be avoided. In order to process protein we have to increase our metabolic rate. Increasing the rate generates heat. Meats, fish, dairy products, poultry and products made with soy beans are all high in protein. Foods that have lower protein levels are your fruits, vegetables and grains. These foods are easy for us to process, which helps keep internal heat down.

External heat can also be managed. One of the easiest ways to protect ourselves from hot, humid weather is to not ride during the hottest part of the day (from about 11:00 AM to about 3:00 PM). Try to plan a route that will have a lot of shade in the af-ternoon. Many times the temperature drops quite a bit in these shady stretches of road. Small roadside parks and similar areas will usually provide relief from the heat. Wal-Mart, K-Mart, upscale grocery stores and some of the larger filling stations provide a place to sit in air conditioned comfort. Install wind deflectors. They help to keep us cool by directing air toward us and can also direct engine heat away from us. Vents in the windshield (if your bike is equipped with one) will help by directing air toward us. Wearing light colored clothing also helps by reflecting some of the sun away from our bodies. Loose clothing lets air circulate, while long pants and boots reduce engine heat on our legs and feet. Neck coolers (fabric tube with very absorbent beads) help keeping our necks constantly moist with cool water. Many people put them in the refrigerator. These do work and stay cold for a couple of hours. Personally I prefer to soak mine in cool water. I find that if I get them too cold then I tend to get a stiff neck. Plant misters aren't just for plants. Try one to spray your shirt or face. Now there is even a pressure mister that looks quite a bit like a drink container. You simply pump air into it (using the built-in pump). Attached to the top is a hose with a nozzle on the end. By pushing a but-ton you direct a fine mist to wherever you point it. A word of caution though. If you are very sensitive to the sun, wetting your shirt may drastically reduce the SPF (Sun Pro-tection Factor) of the shirt. Helmets with vents are helpful along with soaking your hel-met or helmet liner.

The next part of the series will deal with how to prevent and treat heat illness.