Workers can be at more risk inside than in the sun

Nebraska’s heat and the hot work in an oil refinery can teach many lessons about how to protect workers from heat stress. Dwanna Zyla, RN, COHN, occupational health nurse with Memorial/Sisters of Charity Health Network in Houston, and Kirk Koithan, DO, occupational medicine staff physician for St. Luke’s Occupational Health Services in South Sioux City, NE, offer this advice:

• Protect all workers, not just those obviously in danger.

Occupational health professionals automatically think of outside workers first when considering heat stress. That is reasonable because those performing strenuous labor in the midday sun can be at extremely high risk. But don’t overlook those working inside at typical manufacturing plants. The buildings often are not air-conditioned and sometimes are not well-ventilated. If the building is a large steel or metal-framed structure, it can absorb a lot of heat.

"We have a bread plant here in which the inside temperature is 15 degrees warmer in the summer than it is in the winter," Koithan explains. "With a lot of machinery going and poor ventilation, it’s not uncommon for a plant to be hotter inside than if the workers were outside in the summer sun. Those employees can be at great risk of heat stress, and they can be overlooked."

• Explain the serious nature of overexposure to the sun.

In addition to the dangers of heat exhaustion and heat stroke, those working outside must be warned about the danger of sunburn. Con-struction workers, for instance, should be encouraged to wear a hat and keep their shirts on, and they should wear a strong sunscreen. Convincing them of that can be difficult.

Many outside workers have an independent attitude and resist the idea of wearing a sunscreen, Koithan says. To counter that, he explains that overexposure to the sun dramatically increases the chance of skin cancer. Stressing the word "cancer" usually gets people’s attention.

Emphasize the rapid onset of heat stroke.

Workers often do not appreciate how quickly they can progress from simple discomfort in the heat to heat stroke, the most serious and life-threatening problem. (See chart of warning signs for heat stroke, p. 93.)

"In the right circumstances, it can happen in about half an hour. A lot of people will get cramps, feel lightheaded and weak, and then they’ll sit down and tell someone," he says. "It’s the others who try to tough it out and keep going who move on to heat exhaustion and heat stroke. The body warns you if you’ll listen."

Zyla urges workers to play it safe. When considering how dangerous a situation is, she tells workers, "When in doubt, get out!"

Monitor the weather and issue warnings.

The risk of heat stress can rise sharply when exceptionally high temperatures combine with exceptionally high humidity. On those days, every routine precaution becomes more important, and employers must consider the risk of certain activities. Koithan advises monitoring weather predictions and issuing warnings to employers when the conditions look especially dangerous.

Most employers will not step down the work pace, but they may be persuaded to reschedule certain activities for a different time in the day. They also may pass on the warning to workers, strongly encouraging them to take the proper precautions. On-site nurses and department managers may wish to monitor workers more closely on those days, looking for signs of heat stress.