Temperatures creeping to dangerous heights during the summer months put workers at risk for developing heat-related illnesses.

Every year, thousands of workers suffer symptoms of heat-related illnesses that hinder their productivity, sometimes turning fatal; and it can all be prevented. Take the time to know what the risks are and how to stand up to the heat.

Who is at risk?

Heat illnesses are often associated with outdoor workers, but those who work indoors around extreme levels of radiant heat are at risk as well. Aside from working environments, there are several other factors that contribute to a higher risk of experiencing heat stress. New workers who are not acclimated to working in heat for extended amounts of time are more apt to experience symptoms of heat illness due to lack of tolerance. Some medications also affect how the body reacts to heat, such as antihistamines, blood pressure/heart medications, diet pills, laxatives, anticonvulsants, and water pills. In general, people 65 or over, pregnant women, and young children are more susceptible to being affected by heat-related illnesses.

Types of Heat Illness

There are several different types of heat illnesses, all ranging in severity. Physical exertion in hot working environments can cause the body to create more internal heat, which can be intensified by direct sunlight and wearing protective clothing. Sweat is the body’s normal defense against overheating, but high levels of humidity or lack of air movement can stop the evaporation of sweat, limiting the body’s natural ability to cool itself.

Heat Stroke (hyperthermia): This is the most severe type of heat illness, and can be deadly if not immediately treated; it is a medical emergency. During a heat stroke, the core body temperature has exceeded 105.1 °F, and the body has lost the ability to stabilize or lower it. Sweating ceases, making it impossible to get rid of excess heat. Symptoms of heat stroke include: red or flushed skin, rapid but weak pulse, difficultly breathing, dizziness, headache, nausea, vomiting, confusion or bizarre behavior, seizures, convulsions, and unconsciousness. If symptoms of a heat stroke are observed on the job site, call 911 immediately, get the person moved inside or to a shaded area, remove outer clothing and apply cool packs, and vigorously fan them in an effort to cool their core temperature more rapidly. Left untreated, victims of heat strokes can die or retain permanent damage to vital organs.

Heat Exhaustion: Sometimes a predecessor to heat stroke, heat exhaustion is the body’s reaction to excessive loss of water and salt due to continuous sweating. Symptoms can include: excessive sweating, fatigue, dizziness, confusion, nausea, paleness or flushing, muscle cramps, and shallow breathing. Although not as severe as a heat stroke, it is still imperative that an affected person be brought to a cool or shaded area, drinks plenty of water, and applies cool water to their body to combat any worsening of their condition.

Heat Cramps: Heat cramps usually affect workers that sweat vigorously when they are working. Moisture and salt is released from the body rapidly when you sweat, making muscles much more susceptible to injury. Usually, onset does not occur during working activities, but some time after. To protect against cramping, it can be helpful to drink sports drinks and eat potassium rich fruits such as bananas or apples. If cramping does occur while working, it is recommended to rest for several hours to recover, as further exertion could lead to heat stroke or exhaustion.

Heat Rash (prickly heat, miliaria): Some people experience a dermal reaction to excessive heating called heat rash, caused by blockage of sweat glands. This illness is especially prevalent in hot, humid climates. Heat rash presents itself as itchy, red clusters of blisters or pimples, usually on the neck, upper chest, and folds of skin. If a heat rash develops, try working in a cooler environment, if possible, and also keep the affected area clean and dry.

Tips on Prevention

Although ranging in severity, heat-related illnesses and deaths can be prevented.

Assessing Working Environments for Heat Stress Hazards: The wet-bulb globe temperature (WBGT) is often used as an index for potential heat stress hazards in the workplace. It factors in temperature, humidity, wind speed, and radiant heat to come up with an all-encompassing value that will give a measure of how the human body is affected by the environment. Another frequently used measurement is the heat index, which is an index calculated using temperature and relative humidity, but does not factor in direct sunlight, wind speed and direction, or length of exposure . Whichever one is used, they are useful measurements to be used as guidelines that can  ensure workers are not exposed to unbearable heat, and also can be useful in scheduling breaks for employees to make sure they get plenty of rest during the workday. If the weather is just too hot, reschedule the workload.

Employee Training: Employees must know risk factors, both on an occupational and individual basis. Additionally, they should be familiar with signs and symptoms of heat-related illnesses so they are prepared to act accordingly if they or anyone else displays symptoms. All of this information can be provided through regular training programs and availability of reference materials.

Controls: Engineering controls are the most effective form of preventative measure. Whenever possible, ventilation, fans, and/or air conditioners should be installed to provide workers with a cool place to operate in. If hot surfaces are present or equipment radiates heat, proper insulation should be set in place to keep workers safe from radiant temperatures and burns. Shaded areas should also be provided to give outside workers a place to sit and rest out of direct sunshine.

If workers are new to a hot job-site or coming off a leave of absence, they should be provided some time to acclimate to the extreme temperatures during which time their workload is adjusted. Workers should drink plenty of water, and avoid any form of caffeine and alcohol. Remind employees to drink small amounts of water frequently during the day, and also ensure they are eating regular meals and snacks with sufficient salt content.

Health and safety should always be a top priority in the workplace, and when temperatures rise, special precautions need to be taken to prevent against heat stress.




FamilyDoctor.org , Heat Exhaustion and Heatstroke

National Weather Service. Heat Index Chart

Office of Compliance. Fast Facts

OSHA NIOSH. Infosheet

Skinsight, Heat Rash or Prickly Heat (Miliaria Rubra)