Hot weather, especially when combined with strenuous physical labor, can cause body temperatures to rise to unsafe levels—leading to heat illnesses. As an employer, you have a duty to take every reasonable precaution to protect your workers. Under the General Duty Clause, the Occupational Safety and Health Administration (OSHA) Act of 1970, employers are required to provide a workplace free from potential hazards that can cause or are likely to cause death or serious harm to employees, including heat-related hazards.

To protect the well-being of their workforce, employers often need to implement policies and procedures to protect workers in hot environments. Accordingly, any employer that mandates outdoor work or work in hot environments should be educated on heat illnesses. In addition, training employees on heat illness and general safety practices can make all the difference when it comes to protecting them from the heat.

It should be noted, some states have specific standards when it comes to heat illnesses so be sure to check local regulations.

HEAT ILLNESSES

Outdoor workers are especially vulnerable to heat-related illnesses because they spend most of the day outside in direct sunlight.

Normally, the body has ways of keeping itself cool by allowing heat to escape through the skin and evaporating sweat (perspiration). However, if the body does not cool down properly or does not cool down enough, a person may suffer a heat-related illness.

There are a variety of heat illnesses, including heat rash, heat cramps, heat exhaustion and heatstroke. Each of these illnesses vary in symptoms and severity, but commonly cause dizziness, weakness, nausea, blurry vision, confusion, or loss of consciousness.

Heat Rash

Heat rash is a red, bumpy rash characterized by severe itching. Heat rash is often caused by hot, humid environments and plugged sweat glands. It is one of the most common types of rashes and is often uncomfortable and painful.

Heat Cramps

Heat cramps are muscle spasms that usually affect the arms, legs, or stomach. They are the most common type of heat-related illness.

Heat cramps are caused by heavy sweating, especially when water is not replaced quickly enough. Typically, symptoms do not occur until after work, at night or when relaxing. Although heat cramps can be quite painful, they usually don't result in permanent damage.

Heat Exhaustion

Heat exhaustion is a more serious condition than heat cramps. It occurs when the body's internal temperature-regulating system is overworked but has not completely shut down.

In cases of heat exhaustion, the surface blood vessels and capillaries—which are meant to enlarge to cool the blood—collapse from loss of body fluids and necessary minerals. This happens when individuals do not drink enough fluids to replace what they are sweating away.

Common symptoms of heat exhaustion can include the following:

• Headaches
• Heavy sweating
• Intense thirst
• Dizziness or fatigue
• Loss of coordination
• Nausea or vomiting
• Impaired judgment
• Lightheadedness
• Loss of appetite
• Hyperventilation
• Tingling in hands or feet
• Anxiety
• Cool and moist skin
• Weak and rapid pulse
• Low blood pressure

Heatstroke

Heatstroke is a life-threatening illness with a high death rate. It occurs when the body has depleted its supply of water and salt, and the affected individual’s core body temperature rises to deadly levels.

A heatstroke victim may first suffer heat cramps and/or heat exhaustion before progressing into the heatstroke stage—but not always. It is important to note that heatstroke symptoms are similar to those of a heart attack. Therefore, it is especially important to know how to recognize the signs and symptoms of heatstroke and to check for them any time an employee collapses while working in a hot environment.

Symptoms of heatstroke are the same as those for heat exhaustion but can also include any of the following:

• A high body temperature (at least 102 degrees Fahrenheit)
• A distinct absence of sweating
• Hot, red, or flushed dry skin
• Rapid pulse
• Difficulty breathing
• Constricted pupils
• Headache
• Vomiting or confusion
• Bizarre behavior
• High blood pressure
• Fainting
• Seizures
• Excessive sweating
• Nausea

Advanced symptoms may include seizures, convulsions, collapse, loss of consciousness and a body temperature over 104 degrees Fahrenheit.

CONTROLLING HEAT ILLNESSES

There are a variety of ways employers can control heat illnesses in their workplace. Below are some common, yet effective methods, to help keep workers safe.

Heat Illness Assessments

In situations where a worker is exposed or could be exposed to high temperatures, a heat illness assessment should be conducted. This assessment should provide employers with a general sense of the risks facing their employees.

Heat illness assessments should evaluate a wide range of risk factors including workplace temperature, humidity, heat radiation, air movement, employee workload, clothing, and acclimatization.

Employers can use the Heat Illness Assessment Checklist found in the Employer Tools section of this guide.

Heat Illness Control Plans

To protect workers, organizations must take proactive approaches to workplace safety. Once an employer has identified the heat-related risk factors present in the workplace, a heat illness control plan should be developed to reduce exposures. Heat illness control plans typically utilize a mix of engineering and administrative controls to protect workers.

Engineering Controls

Engineering controls are methods that are built into the design of a workplace, piece of equipment or a process to minimize a specific hazard. Engineering controls are often the most effective and preferred method for limiting an employee’s exposure to excessive heat.

The following are some effective engineering controls to consider:

• Automate or mechanize certain processes to reduce a worker’s exposure to heat.
• Reduce radiant heat by covering or insulating hot surfaces.
• Shield workers from radiant heat.
• Increase ventilation or provide air conditioning to remove hot air.
• Practice spot cooling by installing fans.
• Reduce sources of moisture and consider using a dehumidifier.
• Consider using personal, protective equipment, such as thermally conditioned clothing with a self-contained air conditioner or a plastic jacket with pockets that can be filled with ice.

The proper engineering controls vary from workplace to workplace, so it is important to identify opportunities to install or create engineering controls during your heat illness assessment.

Administrative Controls

Administrative controls are changes in work procedures, safety policies, rules, supervision, schedules, and training that reduce the duration, frequency, and severity of heat exposures.

Administrative controls are particularly useful if engineering controls are not practical. This is often the case for outdoor jobs where heat from the environment cannot be controlled.

There are a variety of administrative controls that can help protect workers, and it’s important for employers to pick ones that make sense for the type of work their staff members perform.

Acclimatize Workers

The human body is good at adapting to hot temperatures over time. This process is known as acclimatization, and it allows the human body to modify its own functions to better cope with heat.

Acclimatization has the following benefits:

• Enhanced cardiovascular fitness
• Enhanced sweating
• Lower salt content in sweat

While this process takes time, acclimatized employees will be able to work in hotter conditions for longer periods of time than those who are not acclimatized. According to OSHA, under normal circumstances, adjustment to heat usually takes five to seven days; however, it can also take up to several weeks for the body to fully adjust.

Acclimatization should be done gradually, especially if a worker has never worked in a hot environment. Consider reducing the workload of new workers, giving them just 20% of a normal workload on the first day of acclimatization. You can increase this workload by 10% each day moving forward.

Supervise Workers

In situations where a heat illness could occur, workers should not be allowed to perform job duties unsupervised. Managers should monitor workers closely or require work to be done in pairs or groups.

For added safety, first aid should be readily available and all workers should be trained in applicable emergency procedures.

Manage Work and Rest Cycles

Employers or shift managers will need to oversee schedules in such a way that workers are given adequate time to cool down. Those experiencing a heat illness aren’t always aware they are in danger, and rest periods are crucial to reducing the risk.

The following are some scheduling tips to consider:

• Schedule the most difficult or physically taxing jobs for the coolest part of the day.
• Utilize additional workers or rotate job tasks to reduce the amount of time employees are exposed to heat.
• Allow employees to work more slowly during the hottest periods of the day.
• Relocate work away from direct sunlight or radiant heat whenever possible.
• Schedule routine maintenance or tasks during cooler seasons. For indoor work, these routine tasks should be completed when hot operations are shut down.
• In addition, consider providing employees with cool areas, including shaded or well-ventilated break spots. It should be noted that showering or soaking in cool water can cool the body quickly, and employers should provide these amenities where possible.

Provide Water

Providing cool drinking water is a simple administrative control that can go a long way in safeguarding employees. The human body naturally sweats to cool itself. However, this can result in a significant loss of fluid that must be replenished during the workday.

Require workers to drink water before, during and after work. As a general rule, it’s a good idea for employees to drink about a half a liter of water before beginning work. From there, they should have a glass of water every 20 minutes or so.

Please note that caffeine can cause dehydration, and you should limit workers’ caffeine consumption whenever possible.

Employee Training

Organizations should use the information in their heat illness control plans to train supervisors and workers. Training should include information regarding the following:

• How heat illnesses develop
• Heat illness risk factors in your workplace
• How to prevent heat illnesses
• Workers’ roles in executing the heat illness control plan
• Importance of drinking small quantities of water often
• Acclimatization’s importance, how it is developed and how your worksite procedures address it
• Reporting signs of heat-related illness to supervisors immediately
• Procedures to ensure that directions to the worksite can be clearly provided to emergency medical services

Employees and their supervisors should know how to spot signs of heat illness in themselves and their co-workers. This type of education is critical when it comes to providing timely treatment to those who need it.