Heat injury prevention key during summer months Published July 30, 2008 82nd Training Wing Public Affairs SHEPPARD AIR FORCE BASE, Texas -- During the summer, heat injuries and conditions are something all Sheppard members should be aware of and take steps to prevent. The solid colored flags flown in a half dozen locations around Sheppard are warning levels for the Wet Bulb Globe Temperature heat stress index and are invaluable tool for keeping on top of heat conditions. A green flag indicates a heat index of between 80 and 84.9 degrees; a yellow flag indicates a heat index between 85 and 87.9 degrees; a red flag indicates a heat index between 88 and 89.9 degrees; and a black flag indicates a heat index above 90 degrees. The WBGT takes into account humidity, wind, air temperature, and radiant heat. Radiant heat is heat held and later released by concrete, glass, asphalt and metal. For instance, it may be 106 (degrees) outside one day by the temperature you get from the weather, and be only 82 degrees according to WBGT. The flag system works as follows: White flag (78 to 81.9) -- Normal activity for people accustomed to climate; extremely intense physical exertion may cause heat stroke for people who aren't. No limits light and moderate work; heavy work 40 minutes, rest 20 minutes. Green flag (82 to 84.9) -- Normal activity for those accustomed to the climate; people who aren't should use discretion in planning intense physical activity. No limit light work; moderate work 50 minutes, rest 10; heavy work 30 minutes, rest 30. Yellow flag (85 to 87.9) -- People accustomed to the climate should use caution in planning intense physical activity; those who aren't should curtail strenuous activities. No limit light work; moderate work 40 minutes, rest 20; heavy work 30 minutes, rest 30. Red flag (88 to 89.9) -- Those accustomed to the climate should curtail strenuous exercise and limit conditioning for periods not exceeding six hours; people who aren't should terminate all physical conditioning. No limit light work; moderate work 30 minutes, rest 30; heavy work 20 minutes, rest 50. Black flag (90 and above) -- Light work 50 minutes, rest 10; moderate work 20 minutes, rest 40; heavy work 10 minutes, rest 50. Exercise physiologist John Martin said knowing the index is important because most people are 2 to 3 percent dehydrated before they go outside. The easiest way to beat the heat is to stay out of it, but due to mission requirements, that is not always an option. He said when staying out of the heat is not an option, people need to take preventative steps to avoid heat stress injuries. Drinking enough water is paramount. Mr. Martin said he recommends 8 to 12 ounces of water half an hour before working outdoors, 6 to 8 ounces for every 15-20 minutes working outdoors and another 16 to 24 ounces when have completed outdoor work. "We can't push (drinking water) enough because most people don't get enough, especially with the conditions we have," he said. Drinking too much water could cause water intoxication, but it's a very small percentage of the population that gets water intoxication, so use the recommendations above as a first step. This helps gauge how much you need to take in and adjust it based on physical activity, how much you're sweating and how long you're outside. Almost as important as drinking water is using a work-to-rest ratio - Mr. Martin suggests working 10 to 15 minutes and taking five minutes to get some water and find some shade. He also suggested wearing a dry-fit material such as Under Armor™ because they let the body breathe. Materials like polyester-cotton blends trap heat and sweat against the body and increase the risk of a heat stress injury. Having a higher level of physical fitness will also help you beat the heat Mr. Martin said. For more information on the prevention of heat stress disorders, see Air Education Training Command Instruction 48-101. Watch for the danger signs such as dizziness, nausea, throbbing head, etc. If you recognize these signs, stop running and get prompt medical attention. (Information from a Keesler Air Force base story was used in the writing of this).