The weather is warming up, and summer heat will arrive before we know it. Now is the time to start thinking about preventing heat injuries in yourself and other Soldiers.

The incidence of heat stroke hospitalization in Soldiers has increased eight-fold during the last 20 years, according to the latest Army Heat Injury Prevention Policy Memorandum. Heat injuries can occur in garrison and operational environments, during unit and individual physical training, training exercises, recreational events and even in activities that require very little physical exertion. These injuries are a threat to medical readiness and to the fitness of individual Soldiers.
Commanders and NCOs are charged with putting in place the necessary measures to prevent heat injuries. Medical personnel also have a key role in supporting unit leadership in their efforts to protect Army personnel. In addition, individual Soldiers play a part by following the guidance they are given and paying attention to warning signs in themselves and others.
The primary reference on preventing heat injuries is Technical Bulletin Medical (TB MED) 507, Heat Stress Control and Heat Casualty Management. This guide covers all aspects of heat injury prevention, including heat mitigation procedures, identifying high-risk individuals, heat acclimatization, fluid and electrolyte replacement, work/rest guidelines, management of heat casualties and vigilance. The 2003 Ranger and Airborne School Students Heat Acclimatization Guide also offers practical guidance to allow Soldiers to perform at their best without succumbing to heat-related injuries. A video, Heat Injury II, Prevention and Treatment, is available as well. In addition, the U.S. Army Public Health Command (Provisional) and U.S. Army Research Institute for Environmental Medicine have developed valuable heat injury prevention products, including posters, videos and pocket guides. These products can be found on the Public Health Command's website at
Climate variables (such as temperature and humidity), intensity of activity and individual risk factors interact to cause heat injuries. Individual risk factors include lack of heat acclimatization, cumulative exposure to heat, poor physical fitness, being overweight, concurrent illness, medications/dietary supplements, alcohol use, prior history of heat injury, skin disorders and being over 40 years old. Drinking beverages containing caffeine or alcohol within 48 hours of training also increases the risk of heat injury. Newly mobilized personnel, especially those from cool climates who are not properly heat acclimated, are more at risk of becoming a heat casualty. Additionally, training in a compressed timeframe before deployments also increases risk.
Drinking too much water is also a risk. A number of deaths have occurred in the Army due to water intoxication, an electrolyte disturbance in which the sodium concentration in the plasma is too low. Proper water consumption guidelines should be followed to prevent overhydration. Fluid needs can vary based on individual differences (A,A+- 1/4 quart/hour) and exposure to full sun or full shade (A,A+- 1/4 quart/hour). Hourly fluid intake should not exceed 1A,A1/2 quarts, and daily intake should not exceed 12 quarts.
It is essential that commanders, NCOs and medical personnel are educated on preventing heat injuries and implement a risk-management-based, comprehensive heat injury prevention program. Programs must include identification and assessment of hazards in terms of severity and probability, implementation of appropriate controls to reduce heat injuries and evaluation of the effectiveness of control measures. Early recognition of heat exhaustion is critical to prevent progression to a more serious heat injury and death. (Editor's note: For treatment options for several common heat injuries, see the article "Treat the Heat" on page 22.)
Soldiers will be exposed to extreme heat conditions as their units train for operational missions. Fortunately, heat injuries are preventable, and none need be fatal. Leaders must assess their unit's missions and training requirements against the risks of operating in warm weather environments. Early recognition and treatment of Soldiers showing symptoms of heat injuries is the key to saving lives.