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Home : Safety Promotions : News
NEWS | July 25, 2022

Blog: Preventing Heat Stress on the Flight Line

By Master Chief Aviation Maintenance Administrationman Arlene Williams, Naval Safety Command

Sailors and Marines often work in hazardous environments at their duty stations. Military aviation operations are some of the most dangerous with propellers spinning, jet exhaust blowing, high-powered electrical and radar systems, high-pressure air, high noise, numerous different types of hazardous chemicals required to maintain aircraft and numerous pieces of support equipment constantly moving around work areas. To help protect Sailors and Marines from these hazards, the Navy has required the use of Personal Protective Equipment (PPE) while supporting aviation operations.  

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While required PPE does eliminate potential risk, uniforms and PPE can also add to the #1 flightline safety problem – heat injuries. Wearing prescribed PPE is important, but it is also essential to train aviation support personnel on human factors and to recognize when they are being impacted by high temperatures, which can cause dehydration, fatigue, heat exhaustion, and can lead to impaired thought and slowed reactions. Heat stress, including heat stroke and exhaustion, heat cramps and rashes, sunstroke and loss of physical and mental acuity, can occur in minutes or over time. These conditions can lead to operational disruptions that can be hazardous for mission completion and readiness. Heat “illnesses” are exacerbated by the lack of proper nutrition, exercise, health issues and age, but the condition is aggravated even more in aviation operations due to required PPE and heavy, flame-retardant uniforms. Aviation support personnel must ensure they are staying well hydrated and rotating in and out of extreme heat conditions because lack of adequate hydration is the #1 driver of heat-related injuries and mishaps.

According to Mayo Clinic, heat exhaustion occurs due to dehydration, strenuous activity in heat and heavy perspiration. The symptoms are cool, moist skin with goose bumps, heavy sweating, faintness or dizziness, fatigue, weak or rapid pulse, low blood pressure, muscle cramps, nausea and headaches. The steps to take if you encounter a heat stress issue are: 
  • Move the person out of the heat into a shady or air-conditioned place.
  • Lay the person down, and elevate their legs and feet slightly.
  • Remove tight or heavy clothing.
  • Have the person drink cool water or other non-alcoholic beverage without caffeine.
  • Cool the person by spraying or sponging them with cool water and fanning.
  • Monitor the person carefully; contact a doctor if symptoms worsen or don't improve within one hour.

More serious (heatstroke) symptoms, requiring immediate medical attention, include fainting, agitation, confusion, seizures, inability to drink and core body temperature of 104 F (40 degrees C).

Heat-related injury and risk mitigation best practices on the flightline include, but are not limited to:
  • Enforcing appropriate hydration, sleep, nutrition, health, exercise, acclimatizing programs and temperature monitoring equipment.
  • Work changes such as more frequent breaks, swapping people out more frequently, providing a convenient cool break area, acclimatization activities and using chiller or misting fans where feasible.
  • Adjusting uniform and PPE such as de-blouse to tee-shirt when feasible, cooling vest in extreme heat, alternate head protection devices for hangar maintenance… (do not violate fire, hearing, and chemical exposure protection requirements).
  • Providing safety and heat-mitigation training, including visible signage of dangers in high-heat danger areas, etc.
  • Monitoring self and other personnel (mental/physical acuity quickly decreases) – know the signs, what to do and who to call for additional help.
Maintaining a proper hydration level is the #1 best practice – over-hydration can be worse than dehydration; however, individual hydration levels are somewhat subjective and may require additional analysis by senior personnel to be effective.
  • Drink a minimum of 1-2 quarts of water in a 24-hour period.
  • Avoid alcohol, caffeine and energy drinks altogether, as these actually worsen dehydration.
  • A dehydration warning sign is a dark-colored and/or minimal urine.
Proper hydration is critical for operations in high-temperature environments and is negatively affected by consumption (within 24-48 hours prior) of energy drinks, caffeinated beverages (tea, coffee, soda) and alcohol. Under normal conditions, a person should be consuming one to two quarts of water daily (two quarts = eight, 8-ounce glasses); however, this may not be sufficient for someone who sweats excessively, has health or nutrition issues, or performs duties in high-heat environments, especially if wearing necessary PPE and uniforms. As many Sailors and Marines love energy drinks, they must be cautious to avoid them, on or off duty.
In many military operating locations, the temperature can become significantly elevated during the summer months. Working outside in high-temperature conditions does us no favors in our attempt to keep cool and stay on mission. With this in mind, there are many things our organizations, and we as individuals, can do to mitigate heat-related injury and illness risks.

We should ensure easy access to water and/or, electrolyte-replacement drinks throughout the day. We need designated cool-off areas near work stations, and frequent breaks along with updating training and work procedures are highly recommended. It also helps to place visual reminders in the workspace so all personnel can see them and act accordingly. Individually, we can restrict or minimize our consumption of energy, caffeinated and alcoholic drinks to mitigate the negative impact.

Safety is an all-hands effort and by taking specific preventive measures, personnel can avoid heat stress in aviation operations.