Heat stress can be a deadly threat to workers – and it can be caused by several types of heat sources, including:

• Environmental heat from the sun or excess humidity
• Exertion – the more intense the exertion, the greater the heat risk
• Heat trapped inside heavy or non-breathable work clothing
• Additional heat sources, like ovens or furnaces

Certain health conditions can predispose workers to the dangers of heat stress, but even completely healthy people can be severely harmed by the heat. As such, it’s up to employers and workers to respond to thermal risks and put measures in place to avoid heat-related illness and injury.

What are the Symptoms of Heat Stress and Heat Illness?

When heat stress is intense enough to cause symptoms, the resulting condition is termed heat illness. Two of the most common and concerning forms of heat illness are heat exhaustion and heat stroke. Here are the symptoms and potential complications of each:

• Heat exhaustion – Heat exhaustion is the precursor to heat stroke and merits an immediate medical response from onsite personnel. If untreated, heat exhaustion will progress to potentially deadly forms of heat illness. Common signs of heat exhaustion include headaches, dizziness, heavy sweating, elevated body temperature, nausea or vomiting, and muscle cramps or spasms. Confusion may also be present.
• Heat stroke – Heat stroke is a medical emergency and typically occurs when heat stress goes unchecked for too long. Heat exhaustion may progress to heat stroke suddenly, transitioning from a preventable injury to a potentially life-threatening condition.
  Heat stroke is characterized by dangerously high body temperatures, profuse sweating or a complete lack of it (the body’s attempt to retain water), profound confusion and loss of coordination, slurred speech, mood changes, severe migraine-like headaches and loss of consciousness.

In addition to the above, heat stress may manifest as lower risk heat illnesses such as heat rash or heat cramps. Responding to those mild forms of heat stress is the first step in reducing heat injuries.

Heat Stress Prevention Tips

The best way to handle heat risks is to minimize them from the outset. Failing that, it’s critical that your personnel (including top management) knows how to respond to developing heat-related emergencies. Here are some steps every employer can take to improve their company’s heat safety:

• Identify all potential heat hazards – If you don’t know where the heat hazards are, you can’t protect workers (or yourself) from them. Survey the worksite and determine where heat stress is most likely to emerge. Take temperature readings several times a day over several days to confirm this, as thermal pockets can appear anywhere, including interior spaces.
• Create a heat-specific safety plan – The general recommendation for businesses is to invest in safety planning. If heat hazards are present at your facilities or worksites, a heat-specific safety plan is also recommended. Include all implementable safety measures and who is responsible for implementing them. Putting a plan in place improves emergency readiness if your employees are trained on the steps to take.
• Prioritize medical monitoring – Some people are far more predisposed to heat stress risks than others. People with heart disease and people taking diuretics, anticholinergics or antidepressants are two examples of heat-susceptible workers. If these risk factors are identified in workers early, steps can be taken to mitigate them, like extending the acclimation period or scheduling work rotations away from the worst heat risks.
• Provide essential heat safety resources – Heat stress can be managed with the right onsite materials and resources. For example, neck wraps are a low-cost accessory that workers can use to keep themselves cool.
  Another helpful option is liquid crystal thermometers (LCTs) that workers can easily carry around. LCTs are so light that they can be embedded into ID badges or TWIC cards. They provide an accurate temperature reading within moments and can give workers advance notice of elevated heat risks.
• Prioritize safety training and leadership – Safety planning and other safety measures are no use if workers aren’t put through safety drills. Those measures are also likely to fail if upper management reflects a “safety second” mentality on the job. To ensure neither threatens your heat safety approach, schedule regular training sessions and reject any casual attitudes toward heat safety. It only takes one serious heat injury to derail your organization.
• Implement an acclimation period – Many severe and fatal heat illnesses occur in workers new to the job. These people often have not had time to adjust to high-exertion work or work in high-temperature areas.
  Fortunately, the human body can adjust (to an extent) to these conditions if given a couple of weeks with a gentle ramp-up of work intensity and duration. Allow your new hires to acclimate on this timeline to build up their heat tolerance.
• Have a plan for when heat stress strikes – Ultimately, your organization must be prepared for when, not if, an emergency occurs. These emergency measures should be specified in your safety plan and include details on available emergency resources (such as cooling packs) – and where to find them. Your workers should also know how to move a heat stressed person to safety, how to begin life-saving cooling treatment, and who to contact.

Prevent Heat Stress by Recognizing and Reacting to the Causes

Heat stress can be a killer and has caused dozens of on-the-job fatalities in the last several years. That underestimates the impact of heat illnesses, too, as they often lead to long-term injury and reduced productivity.

The good news is that heat stress and heat injuries are avoidable with the right preventable measures in place.