Summer is here, watch the heat!

  • Published
  • By 1st Lt. Megan M. O'Kane and Tech. Sgt. Richard Charles
  • 7th Medical Group
DYESS AIR FORCE BASE, Texas --  The newest member of the maintenance team, Airman Bones, has labored for two hours on the flightline, racing to beat the clock. He wants to finish his job before shift-change and then later compete in the two-man volleyball tournament. 

A nagging thirst makes him look around for the expediter truck. It's parked on the other side of the ramp. He quickly glances at his hard working coworkers, I must be the only one who is thirsty, he reasons. The expediter truck is too far; I won't be done by shift-change if I go snag a drink at the truck. Thirty minutes later, the job is complete. The caster on his tool dog breaks, so he starts carrying it toward the pick-up point. Ten steps forward he sways. Mistaking the faltering steps for the added weight of the tools, he presses on... Airman Bones awakes surrounded by medical and fire personnel. 

Summer is here! That means shorts and swimming pools, picnics and parades, and outdoor sports. It also means hot weather. The last concern of anyone is heat stress, but it's worth a 5-minute consideration. 

What is Heat Stress and Why Should it Concern me? 

Heat Stress is a negative interaction of the environment, the mission and the worker. Heat causes a body to lose water and salt through sweat. When enough water is lost, the body will overheat. 

Everyone is susceptible to heat stress. It may reduce your physical abilities or cause disorientation, which can result in both lost man-hours and prevention of mission completion. More serious results may be temporary sun aversion, possible hospitalization and if severe enough, death. 

What are the signs and symptoms of heat stress? 

Symptoms that associated with heat stress are:
- Dizziness, nausea, lightheadedness or fainting
- Weakness and moist skin
- Mood changes or irritability or confusion
- Upset stomach or vomiting 

These symptoms are the body's warning that something is wrong and you should take action to prevent them from worsening. 

The more severe symptoms arise when the body stops sweating and the skin becomes hot and dry. This may be accompanied by mental confusion, loss of consciousness or convulsions. If these symptoms present themselves call for help immediately. 

Most bases use a wet bulb globe temperature to determine the heat stress index. The WBGT instrument measures weather conditions and calculates the heat stress index. This device takes into consideration air temperature, solar heat, wind speed and relative humidity. So although reported in degrees Fahrenheit, remember it's not strictly a temperature. In essence, it is trying to simulate how your body is reacting to the environmental conditions. The temperature that is reported on the television, radio and in the newspaper is a measurement of the ambient temperature of the air alone. The WBGT takes into consideration the relative humidity, a variable that factors about 70 percent of the actual WBGT temperature calculation that is reported. The relative humidity plays a big role in how the body is able to dissipate heat. This is why you would see an elevated heat condition sooner, if you were stationed in San Antonio, versus reaching any reportable notification here, even if both areas were reporting similar ambient temperature readings. 

This heat stress index allows the base to give recommendations on an individual's work and rest cycles. The base bioenvironmental engineering office performs health risk-based assessments to determine work conditions in hot environments for various occupations based on their workload and to determine special conditions due to activity, location and clothing. 

How Can I Protect Myself? 

Heat stress prevention is the primary objective. No one can command weather conditions and the heat stress index; however, there are factors within your control that, if heeded, can prevent you from becoming a statistic. 

* The most important factor is to drink water! And that means water! Water consumption should begin prior to activities in the heat, but must start once the activity begins. This cannot be stressed enough. The body's mechanism to identify the need for water is not timely. A person can be dehydrated, or low on water, by 1-2 liters before the body decides to tell you it's thirsty. A small amount of electrolyte replenishing beverages (sports drinks) may be helpful, but will most benefit those unacclimatized (or not conditioned to the local weather.) 

* Avoid caffeinated drinks. They rob your body of water. The morning coffee or occasional soda won't be detrimental, but that "pot a day" or "six-pack a day" requires modification. Also, consider the effects of those new "energy drinks," too. 

* Wear light-colored, loose-fitting clothing, preferably made of cotton. Impermeable fabrics, like nylon or plastic, don't allow the body to naturally cool itself through evaporation or sweating. Covered skin, while it may feel hotter, is more protected. Sunburn can reduce a body's ability to fight heat stress. 

* Be aware that the side effects of drugs, cigarettes, chewing tobacco and (especially) alcohol can reduce the body's ability to combat heat stress. 

* A physically fit body is more efficient at resisting heat stress. 

* Avoid working in direct sunlight if possible. Shaded areas can be 10 degrees Fahrenheit cooler than those in direct sunlight. In all instances, use common sense to govern your activities. 

* Acclimatize as quickly as possible. While conducting physical conditioning in 90 degrees Fahrenheit weather may seem unthinkable to a North Dakota resident, a Florida native might think nothing of physical activity in 100 degrees Fahrenheit. The difference is the climate where you live and the climate where you have adapted. Acclimatization requires a gradual increase in physical activity to reach maximum performance. This is usually accomplished in a period of 7-10 days. 

*Know the signs and symptoms of heat stress. Take action if you notice any of the signs presenting in yourself or others. Find shade or a cool place and drink plenty of water. 

Remember, it's hot out there. Even if there is no flag condition, take precautions when outdoors. Heat stress may not be a riveting topic, but it can kill you. Approximately 4000 Americans died last year with heat stress related injuries. Be smart. Be safe. Stay cool.