Jobsite Best Practices For Mitigating Heat and Cold Stress

Key takeaways from this article:

•      FR and AR garments help prevent injuries from flash fire and arc flash, but managing heat and cold stress requires additional strategies.

•      Effective job site engineering controls can help workers handle extreme temperatures.

•      Utilizing tools like the "OSHA-NIOSH Heat Safety Tool" app can aid in monitoring conditions.

•      Best practices include keeping workers hydrated, scheduling rest breaks, reducing physical demands, providing relief workers, scheduling heavy work during mild parts of the day, providing rest tents, and promoting proper clothing management.

•      Workers should be aware of heat and cold stress symptoms and monitor each other.

•      Understanding body responses to weather, choosing the correct fabrics, and layering can help manage body temperatures.

Employers and safety managers have long looked to flame-resistant (FR) and arc-rated (AR) garments to help protect workers from injury due to flash fire and arc flash. Because these garments are designed using specially engineered, self-extinguishing fabrics and are certified to rigorous testing standards, they can help prevent or lessen the severity of injury.

Utilizing FR/AR garments as part of a comprehensive PPE (personal protective equipment) program is one of the ways employers can meet their obligation to “provide workers with employment and a place of employment that are free from recognized hazards.”1

Questions arise, however, when outside temperatures rise - or plummet. Is it possible to maximize protection while at the same time minimizing the risk of heat stress and cold stress? The answer is yes, but finding the right solution requires an understanding of several interrelated factors, one of them being effective jobsite engineering controls.

In an interview with National Public Radio, occupational physician Ronda McCarthy, MD, MPH, FACOEM said she sees a dramatic decrease in workers’ compensation costs when employers voluntarily adopt many of the measures recommended by the National Institute for Occupational Safety and Health (NIOSH).2

She advises employers and workers to look to NIOSH for recommended heat standards and recommends the “OSHA-NIOSH Heat Safety Tool” app. This mobile app, developed by the Centers for Disease Control and Prevention, provides the current heat index, hourly forecasts, first-aid information and more.

In addition, the following practices should be considered as part of the workday routine:

1. Keep workers hydrated. Provide warm or cool sweetened liquids throughout the day. Avoid caffeine and, of course, alcohol.

2. Schedule plenty of rest breaks. Along with hydration, this is by far the most effective way to avoid heat and cold stress.

3. Reduce the physical demands of workers.

4. Use relief workers or assign extra workers for long, demanding jobs.

5. Schedule the heaviest work during the mildest parts of the day.

6. Provide warming/cooling tents where workers can rest.

7. Help workers avoid or take breaks from the wind.

8. Encourage workers to change out of damp or wet garments before becoming chilled.

9. Adopt acclimatization programs, exposure limits, and rest/work cycles.

10. Know the symptoms of heat and cold stress. Monitor one another, and in emergencies, call 911. Remember that weather affects people differently. Age, fitness and activity levels, body mass index, certain medications, and diet all impact how a person reacts to heat and cold.

The best solution is multi-pronged

There’s no single magic bullet for simultaneously protecting workers from arc flash and flash fire hazards as well the risks of heat and cold stress. PPE alone is not enough, and neither are weather-related engineering controls. However, when combined, and with proper education, you can have quite an effective solution.

In addition to effective jobsite engineering controls, building the right combination for your workers requires an understanding of:

How our bodies respond to hot and cold weather conditions

How various fibers and fabrics can help keep workers cool

How layering can help keep workers warm

With these tools in hand, workers should be able to manage their body temperatures throughout the day and take action as needed to maintain their health and safety.

1 Occupational Safety and Health Act, Section 5(a)(1), 1970.

2 National Public Radio, “As Planet Warms, Advocates Urge U.S. To Set Rules To Protect Workers From Heat,” August 27, 2018,