by Lars Aamoth, CSP
Manager, Charlotte Operations

Across the country this week, temperatures are forecasted to reach record highs in many areas. Heat stress may be thought of as a summertime safety issue; however, it is present indoors year-round due to environmental ambient conditions caused by heat sources from process equipment in certain industries.

What are heat related illnesses and why should your company be concerned?  Heat stress is the when the body cannot reduce the internal temperature by dissipating heat quickly enough. This may lead to a rise in internal body temperature and associated symptoms. Heat stress symptoms include heavy sweating, muscle cramps, headache, rapid pulse, nausea, dizziness, irritability, and thirst. Heat stroke occurs when the body is no longer capable of controlling its temperature. This is a medical emergency and medical attention is required immediately.  Symptoms of heat stroke include rapid temperature rise, hot dry skin, reduced or no sweating, rapid pulse, confusion, loss of consciousness, seizures, and vomiting. 

There are additional risk factors that may contribute to heat related illnesses. These risk factors include employees older than 65 years of age, lack of physical fitness, dehydration, use of certain medications, and workers not acclimated to the work environment, among others. New workers will need one to two weeks to acclimatize to the environmental conditions. The Centers for Disease Control and Prevention (CDC) recommends an acclimatization schedule of 20% exposure on day one and then no more than an additional 20% each additional day. Donning certain types of Personal Protective Equipment (PPE) may also add to an individual workers heat stress. PPE may restrict the body’s natural cooling mechanisms including sweat evaporation and holding excess heat inside. 

An employee exhibiting signs of heat stress should be moved to a cool area, remove unnecessary clothing and PPE, cool the worker with cold compresses, encourage small sips of water, and provide medical attention. If an employee is exhibiting signs of heat stroke dial 911 immediately.  First-aid for heat stroke includes moving employees to cool area, removing unnecessary clothing and PPE, cool the worker quickly with cold compresses on neck, armpits and groin, wetting the skin, provide circulating air, and stay with the employee until medical help arrives.  Heat stroke is a medical emergency and if left untreated, can lead to permanent disability or death. 

Heat related illnesses are preventable and employers should develop a heat related illness protection program incorporated into their broader health and safety program. Engineering controls should be utilized to reduce employee’s exposure to excessive heat and to increase evaporative cooling. Administrative controls can also be utilized, including worker rotations and frequent breaks, to reduce the likelihood of heat related illness. Employees should be encouraged to drink plenty of fluids to stay hydrated and reduce consumption of fluids that like sodas and energy drinks that can lead to fluid loss. 

Assessments of job tasks at risk for heat related illness can be conducted utilizing a Wet Bulb Globe Temperature (WBGT) meter which measures humidity, air movement, radiant heat and temperature. Measurements should be collected at least hourly, during the hottest parts of the day and hottest months of the year. Other factors included during a survey are a clothing adjustment factor and metabolic work rate. Upon completion of the survey, the employer can determine an Action Level (AL) and Threshold Limit Value (TLV) based upon the American Conference of Governmental Industrial Hygienist (ACGIH) recommended values. When limits approach or exceed the AL or TLV, engineering and administrative controls should be utilized to reduce employee exposures to acceptable values.

As the summer heat begins, risk of heat related illness will be with us for several months ahead and year-round in certain facilities. Employers should determine the job positions at risk, develop a heat related illness program, and ensure their employees are protected through engineering controls, administrative controls, or a combination of both. Heat related illnesses are preventable and proper planning should be utilized to ensure the safety of all employees at your facility or job site.

Should you have questions regarding heat-related issues or other industrial hygiene related concerns, please contact Lars Aamoth at (864) 423-5991 or [email protected].