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Photo Information

The antenna station outside the Base Safety Office for the Wet-Bulb Globe Temperature machine. The black device on the left is the actual wet-bulb that uses wind force, barometric pressure, humidity and other factors to determine the actual ambient temperature to the appropriate heat index flag is posted at the front gate of MCLB Barstow.

Photo by Keith Hayes

Keeping it cool during the summer heat

24 May 2019 | Keith Hayes Marine Corps Logistics Base Barstow

Summer starts officially June 21, but as far as Marine Corps Logistics Base Barstow, California is concerned, it’s time to start worrying about the heat now.

“May 1 is when we start taking heat index readings and posting the results at the front gate of the base,” said Mark Reeves, Occupational Safety and Health specialist with the Safety Office aboard MCLB Barstow.

 “The flags used to indicate the temperature and working conditions for the day are, no flag, green, yellow, red, and finally black flag,” Reeves explained.

            •           No flag – The heat index indicates that the conditions do not warrant any heat warning to base employees.

            •           Green flag – The temperature is ranging from 80 F to 84.9 F.

            •           Yellow flag – The temperature is 85 F to 87.9 F.

            •           Red flag – The temperature is between 88 F and 89.9 F.

            •           Black flag – Really hot! Ranging from 90 F and above.

The Safety Office uses a device to measure the temperature that is not just the straight Fahrenheit or Celsius readings.

“We use what is called the Wet-Bulb Globe Temperature system,” Reeves said. “WBGT takes in to account many other factors such as ambient temperature, the humidity in the air, the wind strength, and the barometric pressure to come up with our temperature readings.”

Reeves said when overheating conditions occur in the human body, a number of unpleasant and sometimes fatal reactions occur:

Heat cramps – Painful, brief muscle cramps that occur during or after exercise or work in a hot environment. Muscles may spasm or jerk involuntarily. Cramping may also be delayed and occur a few hours later. Heat cramps are thought to be caused by a deficiency in electrolytes.

Heat stress – Symptoms include headaches, profuse sweating, stomach cramps that might make you throw up, flushed color. Get the victim to the shade, get them water, and loosen restrictive clothing.

Heat stroke – The most severe of heat-related physical conditions. Symptoms include:

High body temperature. A core body temperature of 104 F (40 C) or higher is the main sign of heatstroke.

Altered mental state or behavior. Confusion, agitation, slurred speech, irritability, delirium, seizures, and coma can all result from heatstroke.

Alteration in sweating. In heatstroke brought on by hot weather, your skin will feel hot and dry to the touch. However, in heatstroke brought on by strenuous exercise, your skin may feel dry or slightly moist.

Nausea and vomiting. You may feel sick to your stomach or vomit.

Flushed skin. Your skin may turn red as your body temperature increases.

Rapid breathing. Your breathing may become rapid and shallow.

Racing heart rate. Your pulse may significantly increase because heat stress places a tremendous burden on your heart to help cool your body.

Headache. Your head may throb.

“If you think someone is suffering heat stroke, these are the people that you need to call 911 for and get them into the shade and watered down before medical services arrive,’ Reeves said. “They need to see a doctor now.”

“When conditions are black flag it’s time to curtail your outdoor activities, drink more water, get in the shade and adjust when you go outside, or just stay indoors where it’s cool,” he said.

“If we see someone out there running in black flag conditions we are going to try and get them to slow down or stop their activity,” Reeves said

“But there are certain services that must be provided in any temperature, the emergency services department still has to do its job, cooks still have to serve hungry service members, firefighters still have to fight fires,” he added.

Reeves said fluid intake is key to preventing heat injuries, but it has to be the right kind of fluid.

“A lot of people drink energy drinks all day long, which means they’re dehydrating themselves faster because the caffeine in the coffee and energy drinks is a diuretic, which means it takes water out of the system,” Reeves cautioned. “A good rule of thumb is if you have one energy drink, drink two glasses of water of the same amount to flush the caffeine out of your system.”

“If you tell somebody to drink some water and they say ‘No, I’m not thirsty,’ get them to drink anyway,” Reeves cautioned, “because your body doesn’t tell you right away that you need water. You won’t know until the least opportune time when you fall out and realize you need water.”

If you positively have to work outside, use suntan lotion with a sun protection factor (SPF) of 30 or more, which block ultraviolet rays of the sun and allows a person to stay in the sun longer without burning.

“Reapply frequently,” Reeves said. “It may say waterproof on the bottle but sweat and moisture can wipe that lotion away and you won’t notice until you’re burned.”

Diet also plays a role in keeping your internal cooling system functioning in hot weather.

“Your food intake should include fresh fruit such as watermelon, honeydew, and musk melon, because those have a lot of water content. Eat that for lunch.”

Heat-related afflictions are not forgiving, either, Reeves pointed out. “Once you have heat-related stress or stroke, you’re more susceptible to it again compared to someone who hasn’t had it.”

“My advice is to do your outdoor work early in the morning, wake up your neighbors with the lawn mower, they may want to sleep, but you have to take care of yourself first; wear long-sleeved, light-colored shirts and wear a hat,” Reeves concluded. “Of course the more clothing you’re wearing increases your own body heat, but there are cooler collars, just soak them in water and tie them around your neck and they keep you cooler.”

“You may notice that whenever it gets hot, you won’t see any birds sitting on the powerlines because they don’t like to sit on hot wires,” Reeves said. “They’re all in the trees using the shade to stay cooler.”

“It’s important to pay attention to the heat index flags when you come on base so that you can adjust your outdoor activities, take in more water than usual and be aware that conditions warrant special considerations.

 “Remember, it is everyone’s responsibility to not only look after themselves, but to look after other employees; if you see someone with heat related symptoms, say something and do something about it; you just may save a life.”


Marine Corps Installations West