Here are eight tips from the NIOSH Science Blog on work practices you can use to protect workers from heat stress whether due to work outdoors or indoor thermal conditions:
- Limit time in the heat, increase recovery time spent in a cool environment or both.
- Reduce the metabolic demands of the job, such as by using tools with efficient ergonomic designs or specifically intended to minimize manual strain, or increasing the number of workers per task.
- Train supervisors and workers to recognize early signs and symptoms of heat-related illnesses and to administer appropriate first aid.
- Implement a buddy system where workers observe each other for early signs and symptoms of heat intolerance.
- Some situations may require workers to conduct self-monitoring. A work group, which includes workers, a qualified healthcare provider and a safety manager, should be developed to make decisions on self-monitoring options and standard operating procedures.
- Provide adequate amounts of cool, potable water near the work area and encourage workers to drink.
- If in the heat <2 hours and involved in moderate work activities, drink 1 cup (8 oz.) of water every 15–20 minutes.
- During prolonged sweating lasting several hours, drink sports drinks containing balanced electrolytes.
- Avoid alcohol and drinks with high caffeine or sugar.
- Generally, fluid intake should not exceed 6 cups per hour.
- Implement a heat alert program whenever the weather service forecasts that a heat wave is likely to occur in the following days.
- Institute a heat acclimatization plan and increase physical fitness. Gradually increase time in hot conditions over 7 to 14 days.
- For new workers: The schedule should be no more than 20% of the usual duration of work in the heat on day 1 and no more than 20% increase on each additional day. Closely supervise new employees for the first 14 days or until they’re fully acclimated.
- For workers with previous experience: The schedule should be no more than 50% of the usual duration of work in the heat on day 1, 60% on day 2, 80% on day 3, and 100% on day 4
Safety Clothing Can Expose Workers to the Risk of Heat Stress
Employers have a basic duty to protect workers from foreseeable safety hazards. But they must be careful not to expose workers to one hazard while trying to protect them from another.
The following example which happened in the US is also relevant in Canada, maybe even more so because of worker refusal rights.
A refinery in Louisiana hired a contractor to demolish piping in its sulfuric acid alkylation unit. A 45-year-old pipefitter, who was cutting pipe in four layers of clothing—including a chemical resistant encapsulating suit—died on the job. At the time, the temperature was 83°F (28.3°C).
The US Department of Labor’s Occupational Safety and Health Administration (OSHA) investigated the incident and cited the contractor for failing to implement a heat management program. OSHA specifically noted that employer failed to take into consideration the increased heat stress caused by the specialized clothing being worn by the workers as they cut and removed the piping.
So in the contractor’s well-intentioned and necessary efforts to protect its workers from contact with hazardous chemicals, it inadvertently exposed them to heat stress instead.
Other kinds of PPE , such as respirators, can also increase the risk of heat stress under certain conditions.
Bottom line: When implementing safety measures, consider the impact that such measures may have and any potential safety hazards the measures may create or exacerbate.