Prevent exertional heat illness by monitoring outdoor conditions, hydrating

Staff Sergeant Shaun Martin, a combat medic specialist assigned to Blanchfield Army Community Hospital, drinks from a 16 ounce bottle of water to maintain his hydration in the warm weather. Dehydration occurs when the body uses or loses more fluid than it consumes and doesn’t have enough water and fluid for its normal functions. Dehydration can interfere with athletic performance and result in mild to severe symptoms.

As summer progresses, you can expect variations in environmental conditions that can potentially serve as platforms for exertional heat illness, or EHI.

In terms of definition, EHI refers to a spectrum of disorders ranging from dehydration, mild heat cramps, heat exhaustion to heat stroke.

“Weather conditions in the Fort Campbell area can be dangerous and should be watched closely to avoid possible heat illness cases,” said Col. Kathryn Ellis, Blanchfield Army Community Hospital chief of Preventive Medicine.

The Fort Campbell area is prone to high humidity and heat, when these are combined it leads to an increased heat index.

“This can be extremely dangerous to individuals who have prolonged exposure to the outdoors and especially to individuals exerting intense activity without proper breaks and hydration,” Ellis said.

Staying hydrated is vital in preventing EHI. In terms of drinking water for hydration, it is recommended that you do not consume more than 1.5 quarts per hour and no more than 12 quarts per day. Drinking more water than the body can excrete through sweating and urination can lead to water intoxication (i.e., hyponatremia), a condition that requires medical attention.

You can gauge your hydration status first thing in the morning by noting the color and volume of your urination. A dark, low volume and infrequent urination is an indication that your fluid consumption needs to be increased.

If you are not acclimatized to the heat, it is recommended that you limit the intensity and duration of activities such as physical work and exercising performed in hot weather. Recommended acclimatization requires about two weeks of progressive heat exposure, with rest periods, while performing applicable activities in the heat. It is worth mentioning that maintaining a high physical fitness also is important given that very fit people will acclimatize faster to the heat than those who are less fit.

When feasible, it is important that your schedule is set up in a manner that the most physically strenuous activities take place early in the morning and not during the hottest part of the day. Given that there is a cumulative effect of repetitive days of activities performed in hot conditions, you also should consider modifying your schedule based on the previous day’s weather and activities. For instance, if you performed a 12-mile road march in the heat on the previous day, it is advisable that you postpone performing a similar strenuous activity in the heat on the following day.

Proper clothing should be taken in consideration. The Centers for Disease Control and Prevention recommends wearing lightweight, light-colored and loose-fitting clothing that helps sweat to evaporate. For military personnel, leaders should consider uniform modification for Soldiers operating under various heat conditions. Such uniform modifications include and are not limited to Soldiers un-blousing their trouser legs, unbuckling their web belts and removing their Operational Camouflage Pattern tops.

Sunburn impacts the body’s ability to cool down that can result in dehydration. You can protect yourself from the sun by putting on sunscreen that has a sun protection factor, or SPF, of 15 or higher. Sunscreen should be applied 30 minutes before going outside and reapplied as needed according to the manufacturer’s directions. Specifically, the CDC recommends sunscreens that are broad spectrum or have UVA and UVB protection as these products work best.

It is worth mentioning that heavy sweating removes water and electrolytes such as salt, calcium and potassium from the body. Not replacing fluids and electrolytes lost during strenuous activities could result in dehydration. You should consider sports drinks as an effective source for electrolytes replacement during prolonged periods of profuse sweating in hot weather. Select people, such as those on low-salt diets, or those who have diabetes, high blood pressure or other chronic conditions should consult with their medical providers before drinking sports beverages.

It also is important that to pay attention to weather forecasts and heat alerts. When gauging the potential effect of environmental conditions on your body, the outside air temperature should not be the only variable that you consider. Other environmental conditions such as humidity, wind speed, sun angle and cloud cover are equally as important. The wet bulb globe temperature, or WBGT, combines the noted environmental conditions into values associated with various heat categories. Each heat category has recommended work and rest cycles and hydration requirements.

At Fort Campbell, the WBGT index is monitored hourly, 7:30 a.m.-4 p.m. Mondays -Fridays, by Blanchfield Army Community Hospital’s Department of Preventive Medicine. You can obtain the WBGT index by calling 270-798-4328. During nonworking hours, the WBGT index can be obtained by contacting Range Control at 270-798-3001. It is important to note that WBGT index monitored by BACH’s Preventive Medicine and Fort Campbell’s Range Control may not necessarily reflect the environmental conditions at other locations across the installation; hence, should only be used as a guideline. Applicable units should consult their Preventive Medicine assets or field sanitation teams on monitoring the WBGT index within their operational areas, especially during training activities outside, when the outside air temperature exceeds 75 degrees.

It may appear logical for you to be concerned about EHI prevention only during the summer, however, this concern should be all year-round. Based on an analysis conducted by the U.S. Army Public Health Center, it was reported that 17% of 7,827 documented cases of EHI cases at various U.S. Army installations occurred during non-summer months.

Recommended for you