"Two Firefighters Succumb to Heat" were the headlines of a newspaper article the day after a chemical spill at a loading dock. The firefighters were entry team partners of mine from our hazardous material response team when we responded to a spill of formalin, a liquid consisting of formaldehyde, water, and methanol. A dock worker at a central facility at our local university dropped a cardboard box containing four-one liter bottles and the leak quickly soaked and spilled around the box. Being highly toxic and a carcinogen the workers cleared the area and called for help. Our fire department responded and the hazmat team decided to suit-up in Level A to make an entry and make an assessment.
The critical factor in this incident was the weather. We were in the middle of a heat wave that not only brought high temperatures but also high humidity. The day of the spill the temperature was well into the 90's by 1100 hours with a 40% humidity level. When our entry was made shortly before noon the heat index, a value that combines heat and humidity, made the environment feel like 95F. Still, we forged ahead by suiting up our three-person entry team. As we entered the hot zone and before we were in the building one of our team members motioned that he had to exit. The entire team abruptly turned and exited the hot zone. Shortly after we peeled off our Level A suits we learned that our teammate was suffering from extreme heat exhaustion. As he was attended to by paramedics the other teammate and I re-suited and re-entered the hot zone.
We located the spill area and began to containerize the broken bottles when my partner communicated to me that he also had to exit. We hurriedly left the area and underwent decontamination. We both doffed our suits and my partner was promptly treated by other paramedics. As a result of wearing Level A suits and in response to the extreme heat burden both of my partners were treated on location with intravenous (IV) fluids and cooling measures. Both entry members were transported and kept overnight at a hospital because of heat exhaustion. I was lucky-in comparison: I endured minor heat stress from the hazmat emergency. Another factor that contributed to these heat injuries was that the two firefighters who were transported were dehydrated from alcohol consumption the day before from attending a golf outing.
The time of year to raise our awareness to the signs of heat stress is upon us. The effects of heat on the human body can be devastating and life threatening for both firefighters and hazmat personnel. For firefighters heat stress causes more demand on the heart and the body's cooling system and if heat is not dissipated can lead to severe health problems such as heart attack. Likewise, hazmat personnel in chemical suits also endure a high heat load during hot weather. In fact, many more injuries occur to hazmat personnel as a result of heat stress than from chemical exposure each year. To better enable responders to avoid and manage heat stress, prevention measures and strategies need to be developed and employed.
Perhaps the first place to start is with the signs and symptoms that are displayed by a person under heat stress or hyperthermia. The following is the progression of heat stress if undiagnosed or untreated.
A minor form of heat stress resulting from clothing irritating skin due to moist and hot conditions. Easily treated by good personal hygiene and clean, dry clothing.
Moderate dehydration can cause muscles to cramp or have spasms. Treatment includes proper hydration and a diet with adequate salt can assist in preventing cramps.
This is the most common type of injury incurred by hazmat personnel. It occurs with loss of fluids by perspiring and can also result in cramps. Profuse sweating and lack of energy are also signs of early heat exhaustion. Treatment is with proper fluid replacement and cooling of the body.