What to do, not do when the flag changes color

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  • By 81st Aerospace Medicine Squadron
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KEESLER AIR FORCE BASE, Miss. --  During the summer, the bioenvironmental engineering flight performs wet bulb globe temperature readings that determine a heat category and work/rest cycles.

The WBGT is often confused with the heat index, which is a measurement of ambient temperature, including the effect of relative humidity. WBGT requires special monitoring equipment for humidity, ambient temperature and solar loading.

WBGT readings can change significantly during the day depending on how quickly the weather changes. BEE and base fitness center personnel take WBGT measurements when a high temperature of 85 degrees is anticipated. From June 1 to Sept. 30, WBGT readings are observed between 8 a.m. to 5 p.m.

WBGT readings are disseminated through the base command post so supervisors can determine and implement work/rest cycles accordingly. Flags of various colors are posted at base fitness centers and the Triangle to designate the heat level at different times throughout the day.

Here's the information used to determine the rest-work cycle is based on Air Education and Training Command Instruction 48-101, Prevention of Heat Stress Disorders:

White flag -- 78 to 81.9 degrees. Easy work with no work-and-rest limit; water intake ½ quart an hour. Moderate work, no work-and-rest limit; water intake ¾ quart an hour. Hard work, 40 minutes of work and 20 minutes of rest; water intake ¾ quart an hour.

Green flag-- 82-84.9 degrees. Easy work with no work limit; water intake ½ quart an hour. Moderate work, 50 minutes work and 10 minutes rest; water intake ¾ quart an hour. Hard work, 30 minutes work and 30 minutes rest; water intake one quart an hour.

Yellow flag-- 85-97.9 degrees. Easy work with no work and rest limit; water intake ¾ quart every hour. Moderate work, 40 minutes of work and 20 minutes rest; water intake ¾ quart an hour. Hard work, 30 minutes of work and 30 minutes rest; water intake one quart an hour.

Red flag-- 88-89.9 degrees. Easy work, no work-and-rest limit; water intake ¾ quart an hour. Moderate work, 30 minutes of work and 30 minutes rest, water intake ¾ a quart an hour. Hard work, 20 minutes work and 40 minutes rest, water intake one quart every hour.

Black flag-- 90 degrees or more. Easy work, 50 minutes work and 10 minutes rest, water intake one quart an hour. Moderate work, 20 minutes work and 40 minutes rest; water intake one quart an hour.

The WBGT flag condition is available on the Keesler Intranet via the Air Force Portal and the base "giant voice" announcement system for black flag conditions. This allows base personnel with computer access to identify the current flag conditions and make wise choices while working outside. With hot weather engulfing south Mississippi, it's time to prepare for and prevent heat-related injuries.

There are three types of heat related illnesses: cramps, exhaustion and stroke. All are easily preventable.

First, drink plenty of non-caffeinated, non-alcoholic fluids. Anyone planning to do exercise or heavy work in the heat should drink a glass or two a few hours before starting and continue to drink something throughout the day.

Second, people need to eat a well-balanced diet and try to avoid alcohol and caffeine until work in the heat is done. Anyone taking medications or on a special diet should check with a physician before performing heavy work or exercise in the heat.

Third, establish an adequate work and rest cycle. A person's body indicates if limits have been pushed. It is important to intervene and stop the progression of a heat injury since heat stroke can result in brain damage or even death. If a person is thirsty, has a headache or becomes dizzy, he or she needs to take a break, cool off and drink fluids. These are early signs of heat stress.

If a person becomes unsteady, weak or has muscle cramps that don't go away with rest and fluids, he or she should seek medical attention.

If someone is confused, not responsive or vomiting, get them in the shade, take off any excess clothing and call for medical assistance. If they aren't perspiring, try to help them cool off by fanning them or dabbing their face and neck with a cool cloth. However, don't throw or pour cold water on them.


For more information about heat-related illnesses, call public health, 228-376-3163. For more information related to heat conditions, call bioenvironmental engineering, 228-376-0590.