Officials Caution Sailors About Heat Levels as Temperatures Rise

By Mass Communication Specialist 1st Class (SW) Ardelle Purcell, National Naval Medical Center Public Affairs

BETHESDA, Md. (NNS) -- National Naval Medical Center's (NNMC) Preventive Medicine department is advising Bethesda staff, contractors and patients to keep it cool as weather forecasters predict an extremely hot summer season.

"The heat index is what it actually feels like outside," said Hospital Corpsman 2nd Class Beau Tice, a Preventive Medicine technician. "It's basically a number complied from the temperature outside with the humidity in the air. The hotter it is outside, the more likely you are to succumb to a heat injury such as heat cramps, heat stress, heat stroke or heat exhaustion."

The human body normally cools itself by sweating, which evaporates and releases heat from the body. However, when the humidity is high, the evaporation rate is slow, and heat doesn't leave the body as quickly as it normally would. This can cause heat-related injuries.

"Increased humidity reduces your ability to cool on your own," said Hospital Corpsman 1st Class Lawrence Coomer, leading petty officer of the preventive medicine department. "If you're already kind of wet from the environment, you're not going to sweat as much so your body is not going to cool naturally. The more humid it is, the worse off you are."

To help avoid heat-related injuries, the Preventive Medicine department uses the wet bulb globe temperature (WBGT) to calculate the heat index or what it actually feels like outside. Once that temperature is determined, the heat condition flag warning system (color-coded flags) is used as a guide for physical training and for those working outside onboard the Bethesda campus.

"Black flag, you really shouldn't be [exercising] outside," said Tice. "Red flag [means] you should be well hydrated because it's hot. Green and yellow flags are saying it's starting to get hotter out, you need to be aware of this."

For avid runners, sports extremists, construction workers or those with medical conditions requiring medication, Tice recommends becoming familiar with the flag system.

"If you are [exercising] outside in the summertime, you should be well hydrated. The muscle is like a sponge, if it's dry it will break. If you try and bend a sponge when it's dry, it'll break. But if you keep it hydrated and wet, it will be flexible and pliable. For those that work outside, you have to know the work-rest cycle."

According to the Centers for Disease Control and Prevention, the warning signs for heat exhaustion include: heavy sweating, paleness, muscle cramps, tiredness, weakness, dizziness, headache, nausea or vomiting and fainting. The skin may be cool and moist. The pulse rate will be fast and weak, and breathing will be fast and shallow. If heat exhaustion goes untreated, it may progress to heat stroke.

"When you get to the heat stroke stage, your skin is dry and clammy because your body no longer has the ability to cool you," said Tice. "It's now keeping the water inside to make use of what little it has left."

The Preventive Medicine department recommends drinking plenty of cool nonalcoholic beverages, getting proper rest, keeping cool in an air-conditioned environment, wearing lightweight clothing and sunscreen to avoid heat-related injuries.