What is Heat Stress?

Heat stress is a buildup of body heat generated either internally by muscle use or externally by the environment. Heat exhaustion and heat stroke result when the body is overwhelmed by heat. As the heat increases, body temperature and the heart rate rise painlessly. An increase in body temperature of two degrees Fahrenheit can affect mental functioning. A five degree Fahrenheit increase can result in serious illness or death.

During hot weather, heat illness may be an underlying cause of other types of injuries, such as heart attacks, falls and equipment accidents. The most serious heat related illness is heat stroke. The symptoms are confusion, irrational behavior, convulsions, coma, and death. While over 20% of heat stroke victims die regardless of health or age, children seem to be more susceptible to heat strain than adults. In some cases, the side effects of heat stroke are heat sensitivity and varying degrees of brain and kidney damage.

Preventing heat stress will:

• Protect Health – Heat illness is preventable and treatable before it is life threatening.
• Improve Safety – Any heat stress can impair functioning.
• Increase Productivity – People work slower and less efficiently when they are suffering from heat stress.

Employers, supervisors and workers all have an essential role to play in preventing heat stress. Each member of the team should use good judgment to prevent heat related illness. A heat stress control program should protect all workers at the operation, from those who can work comfortably in heat to those in poor physical shape.

Key elements for controlling heat stress are:

• Drink one glass of water every 15 to 30 minutes worked, depending on the heat and humidity. This is the best way to replace lost body fluid.
• Read medication labels to know how cause the body to react to the sun and heat.
• Avoid alcohol and drugs as they can increase the effects of heat.
• Build up tolerance for working in the heat. Heat tolerance is normally built up over a one to two week time period.
• Take breaks to cool down. A 10–15 minute break every two hours is effective.
• Adapt work and pace to the weather.
• Provide heat stress training to workers and supervisors.
• Manage work activities and match them to employees’ physical condition.