#95 Preventing Heat Stress

Most heat-related health problems can be prevented or the risk of developing them reduced. Following are a few basic precautions that should lessen heat stress:

  1. A variety of engineering controls including general ventilation and spot cooling by local exhaust ventilation at points of high heat production may be helpful. Shielding is required as protection from radiant heat sources. Evaporative cooling and mechanical refrigeration are other ways to reduce heat. Cooling fans can also reduce heat in hot conditions. Eliminating steam leaks will also help. Equipment modifications, the use of power tools to reduce manual labor and personal cooling devices or protective clothing are other ways to reduce the hazards of heat exposure for workers.
  1. Work practices such as providing plenty of drinking water – as much as a quart per worker per hour – at the workplace can help reduce the risk of heat disorders. Training first aid workers to recognize and treat heat stress disorders and making the names of trained staff known to all workers is essential. Employers should also consider an individual worker’s physical condition when determining his or her fitness for working in hot environments. Older people, obese workers, and personnel on some types of medication are at greater risk.
  1. Alternating work and rest periods with longer rest periods in a cool area can help workers avoid heat stress. If possible, heavy work should be scheduled during the cooler parts of the day and appropriate protective clothing provided. Supervisors should be trained to detect early signs of heat stress and should permit workers to interrupt their work if they are extremely uncomfortable.
  1. Acclimatization to the heat through short exposures followed by longer periods of work in the hot environment can reduce heat stress. New employees and workers returning from an absence of two weeks or more should have a 5-day period of acclimatization. This period should begin with 50% of the normal workload and time exposure the first day and gradually building up to 100% on the fifth day.
  1. Employee education is vital so that workers are aware of the need to replace fluids and salt lost through sweat, can recognize dehydration, fainting, heat cramps, salt deficiency, heat exhaustion, and heat stroke as heat disorders. Workers should learn the importance of daily weighing before and after work to avoid dehydration.