WRIGHT-PATTERSON AIR FORCE BASE, Ohio – During the summer months outdoor heat is measured with wet bulb globe temperature readings.
The WBGT is different from the heat index, which is a measurement of ambient temperature. Unlike the heat index, WBGT accounts for wind, cloud cover, and sun angle and is measured in direct sunlight.
By measuring in this manner and including these factors, the WBGT can measure heat stress in direct sunlight, allowing for the most accurate recommendation on what precautions are necessary.
Because of all the different factors that go into the measurement, WBGT readings can change significantly during the day depending on how quickly the weather changes, so the most up-to-date information on WBGT test are disseminated across the base.
Excessive heat can cause a variety of ailments, such as heat rash, heat cramps, heat syncope, heat exhaustion, and heat stroke. While some of these, such as heat rash, are inconvenient, heat exhaustion and heat stroke can be extremely dangerous.
Those experiencing heat exhaustion will feel weak and feverish; they will often appear flushed. Someone experiencing heat exhaustion may even faint. A person displaying symptoms of heat exhaustion should be taken somewhere cooler and shaded and given fluid immediately.
However, the 88th Air Base Wing Emergency Management office reminds everyone that fluids should never be given orally to an unconscious person, as it could cause serious injury or even death.
Even more dangerous than heat exhaustion is heat stroke. Heat stroke occurs when the body’s cooling defense mechanisms become overwhelmed and the body’s core temperature continues to rise. This can lead to permanent brain damage and even death. If someone is experiencing heat stroke, efforts should be made to lower the victim’s temperature.
If experiencing any symptoms of heat stress, one should seek relief immediately to prevent serious illness.
The Department of Defense utilizes the WBGT to determine the following heat categories and work/rest cycles for outdoor activities and physical work:
White flag — 78 to 81.9 degrees. Easy work with no work/rest limit; water intake ½ quart an hour. Moderate work, no work/rest limit; water intake ¾ quart an hour. Hard work, 40 minutes of work/20 minutes of rest; water intake ¾ quart an hour.
Green flag — 82-84.9 degrees. Easy work with no work/rest limit; water intake ½ quart an hour. Moderate work, 50 minutes work/10 minutes rest; water intake ¾ quart an hour. Hard work, 30 minutes work/30 minutes rest; water intake one quart an hour.
Yellow flag — 85-97.9 degrees. Easy work with no work/rest limit; water intake ¾ quart every hour. Moderate work, 40 minutes of work/20 minutes rest; water intake ¾ quart an hour. Hard work, 30 minutes of work/30 minutes rest; water intake one quart an hour.
Red flag — 88-89.9 degrees. Easy work, no work/rest limit; water intake ¾ quart an hour. Moderate work, 30 minutes of work/30 minutes rest, water intake ¾ a quart an hour. Hard work, 20 minutes work/40 minutes rest, water intake one quart every hour.
Black flag — 90 degrees or more. Easy work, 50 minutes work/ 10 minutes rest, water intake one quart an hour. Moderate work, 20 minutes work/40 minutes rest; water intake one quart an hour. Hard work, 10 minutes work/ 50 minutes rest; water intake one quart an hour.
Even following these categories, certain groups may be more susceptible to heat stress, such as pregnant women, elderly people, and individuals who are taking certain medications.
To help combat the heat, if possible, begin shifts earlier in the day, try to drink one cup of cool water every 15 to 20 minutes even if you are not thirsty, avoid drinks containing caffeine or alcohol as they promote a loss of fluids, and take adequate periods of rest.
