Heat Stress

Heat stress can be a major concern in workplace environments potentially causing irritability, low morale, absenteeism, short cuts in procedures and unsafe behavior. In extreme cases heat stress, in the form of heat stroke, can be fatal.

Excessive exposure to heat can seriously impact worker health, safety and productivity. Accurate measurement of environmental conditions along with use of PPE that can minimize or reduce worker heat load can help reduce the risk of heat strain.

What Are the Heat Stress Warning Signs?

If the body cannot get rid of excess heat, it will store it. When this happens, the body's core temperature rises and the heart rate increases. As the body continues to store heat, the person begins to lose concentration and has difficulty focusing on a task, may become irritable or sick, and often loses the desire to drink. The next stage is most often fainting and even death if the person is not cooled down.

Symptoms of heat exhaustion

• Headaches, dizziness, lightheadedness or fainting
• Weakness
• Moist skin
• Mood changes such as irritability or confusion
• Upset stomach or vomiting

Symptoms of heat stroke

• Dry, hot skin with no sweating
• Mental confusion or losing consciousness
• Seizures or convulsions

References

Heat Stress." Occupational Safety & Health Administration. Accessed May 20, 2013 http://www.osha.gov/SLTC/heatstress/index.html.

How Do You Know If It is Too Hot?

The main factors leading to heat stress include strenuous physical activity, high air temperature, high humidity, direct contact with hot materials, and radiant heat sources. Total heat load on a body is the combination of environmental conditions, clothing and metabolic or work load factors. According to the American Conference of Governmental Industrial Hygienists (ACGIH®), the Wet Bulb Globe Temperature (WBGT) can be useful in evaluating the environmental contribution to heat stress [ACGIH 2013]. The WBGT can then be used with the ACGIH® Heat Stress and Heat Strain Threshold Limit Value (TLV®) to assess worker exposure as part of an overall heat stress program. The WBGT measurement may also help identify environmental conditions that can contribute significantly to heat stress. That, in turn, may help identify ways to reduce the environmental heat load on a worker. References 1. American Conference of Governmental Industrial Hygienists (ACGIH). (2013) Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati: American Conference of Governmental Industrial Hygienists.

How Can Heat-Related Illness Be Prevented?

Heat-related illnesses can be prevented. Important ways to reduce heat exposure and the risk of heat-related illness include engineering controls, such as air conditioning and ventilation, that make the work environment cooler, and work practices such as work/rest cycles, drinking water often, and providing an opportunity for workers to build up a level of tolerance to working in the heat.1 Excessive exposure to heat can seriously impact worker health, safety and productivity. Accurate measurement of environmental conditions along with use of PPE that can minimize or reduce worker heat load can help reduce the risk of heat strain. 3Mâ„¢ Heat Stress Monitors can help evaluate the work environment, while 3M reflective products and powered and supplied air respirators can help minimize the heat load on workers.

References

1.Heat Stress." Occupational Safety & Health Administration. Accessed May 20, 2013 http://www.osha.gov/SLTC/heatstress/index.html.

View Heat Stress Tools & Resources Heat Stress Information

• Video:Introduction to Heat Stress Monitors
• eLearning Course on Occupational Heat Stress Monitoring [Safety eLearning, Page 1.4.3.4]

Related PPE Resources

• 3M Detection [Detection Services, Page 1.1.3.2]
• 3M Protective Apparel [Protective Apparel, Page 1.1.3.13]
• 3M Head & Face Protection [Head and Face Protection, Page 1.1.3.4]

Quick Links

• CDC Heat Stress [http://www.cdc.gov/niosh/topics/heatstress/]
• OSHA Heat Exposure [https://www.osha.gov/SLTC/heatstress/index.html]