Worker exposure to excessive heat from working in hot environments, such as boiler rooms, can lead to heat stress-related illnesses, such as heat exhaustion and heat stroke.
Exposure to excessive heat can result in heat exhaustion and heat stroke. At high temperatures, the body circulates significant amounts of blood to the skin in an effort to eliminate heat through perspiration. As a result, less blood is circulated to the body's vital organs including the brain. Heat exhaustion can lead to dizziness, blurred vision, nausea, and eventual collapse. If not treated promptly, by lowering the person's body temperature, a person suffering from heat exhaustion could suffer brain damage.
Even more serious than heat exhaustion is heat stroke. During heat stroke the body stops sweating, making it impossible to dissipate heat. The body temperature may rise to a dangerously high level in a short time and may cause death.
Recognized Controls and Work Practices
Recognized work practices include educating and training employees and supervisors to detect early signs of heat-related illness and have available first-aid workers to treat these illnesses.
- Recognize the first signs of heat exhaustion (e.g., dizziness, lightheadedness, weakness, blurred vision, nausea) and take immediate action to lower the employee's body temperature to prevent the progression of symptoms.
- Remove workers suffering from heat exhaustion from the hot environment and immediately given cool water to drink. Lay them on their back and raise their legs. If they are sick to their stomach lay them on their side. If the person does not feel better in a few minutes call for emergency help.
- Recognize the signs of heat stroke (which can be fatal). The symptoms are severe headache, mental confusion, loss of consciousness, flushed face, and hot, dry skin, with no sweating. If someone has stopped sweating, seek medical attention immediately. If a worker shows signs of possible heat stroke, obtain professional medical treatment immediately.
- Place the worker in a cooler, well-ventilated area and remove outer clothing. Keep the worker's skin wet and increase air movement around the worker to improve evaporative cooling until professional methods of cooling are initiated and the seriousness of the condition can be assessed. Replace fluids as soon as possible. The medical outcome of an episode of heat stroke depends on the victim's physical fitness and the timing and effectiveness of first aid and medical treatment.
Also, assess worksites for potential hot work environments and identify and address ways to decrease heat hazards in these areas. For example, use recognized engineering, work practice, and administrative controls, and personal protective equipment, including:
- General ventilation and local exhaust ventilation at points of high heat production.
- Spot cooling fans.
- Evaporative cooling and air conditioning.
- Protective clothing and equipment.
- Provide plenty of drinking water.
- Acclimatize, or gradually introduce employees to the hot environment, because the body gradually builds up a tolerance to high temperatures. This process usually takes up to 2 weeks.
- Have employees wear light, loose-fitting, breathable (like cotton) clothing.
- Consider the employee's physical condition and recognize that older or obese workers and personnel on some types of medication are at greater risk.
- Assign these workers to jobs where heat stress is not an issue, if feasible, or, if not feasible, rotate these workers out of situations where heat stress is an issue on a more frequent basis.
- Provide training on the danger of using drugs, including therapeutic ones, and alcohol in hot work environments.
- Have employees avoid using caffeine and alcoholic beverages while working in hot environments. These beverages make the body lose water and increase the risk for heat illnesses.
- Alternate work and rest periods. Encourage frequent short breaks in cool areas to allow your body to cool down.
- Monitor temperatures, humidity and workers' responses to heat at least hourly.
- Train supervisors to detect early signs of heat-related illness and permit workers to interrupt their work if they are extremely uncomfortable.
- Educate employees to recognize the need to replace fluids and salt lost through perspiration.