Colorado has experienced some of the hottest days on record in the last month. As temperatures rise, so does the risk of heat-related illnesses on job sites. Although illness from exposure to heat is preventable, every year, thousands become sick from occupational heat exposure, and some cases are fatal.
Most fatalities, 50% to 70%, occur in the first few days of working in warm or hot environments because the body needs to build a tolerance to the heat gradually over time. The process of building tolerance is called heat acclimatization. Lack of acclimatization represents a major risk factor for fatal outcomes.
Protecting yourself and others from heat stress, heat exhaustion, and heatstroke is essential for maintaining a safe work environment. Remember, water, rest, and shade are best for keeping your team members safe.
Water
Employers should provide cool water for workers to drink, proper hydration is essential to prevent heat-related illness. Workers should be encouraged to drink at least one cup (8 oz) of water every 20 minutes while working in the heat, not just if they are thirsty. Workers should not rely on feeling thirsty to prompt them to drink. They should be reminded to drink on a regular basis to maintain hydration throughout their shift.
For longer jobs in the heat, employers should provide electrolyte-containing beverages such as sports drinks. Workers lose salt and other electrolytes when they sweat. Substantial loss of electrolytes can cause muscle cramps and other dangerous health problems. Water alone cannot replace electrolytes.
Rest
When heat stress is high, employers should require workers to take breaks. The length and frequency of rest breaks should increase as heat stress rises. In general, workers should be taking hourly breaks whenever heat stress exceeds the limits shown in OSHA’s Table 2 for heat illness rest break schedule.
Breaks should last long enough for workers to recover from the heat. How long is long enough? That depends on several factors including environmental heat and the worker’s physical activity level, as well as the individual worker’s personal risk factors. The location of the breaks also matters. If workers rest in a cooler location, they will be ready to resume work more quickly.
Some workers might be tempted to skip breaks. In hot conditions, skipping breaks is not safe! Employers should make sure that workers rest during all recommended break periods. Both NIOSH and ACGIH have recommendations on appropriate lengths of work and rest cycles as a function of the workload and the WBGT (ACGIH 2017, NIOSH 2016)
Shade
Workers should be given a cool location where they can take their breaks and recover from the heat. When outdoors, this might mean a shady area, an air-conditioned vehicle, a nearby building or tent, or an area with fans and misting devices. Indoors, workers should be allowed to rest in a cool or air-conditioned area away from heat sources such as heaters.