Heat illness can strike any person, at any time and place, regardless of physical activity level. People engaging in outdoor work such as construction, landscaping, utility work, agriculture, road maintenance, delivery work, and many others can expect to be working in the sun for long periods of time. This can quickly become hazardous as temperatures climb.

Heat-related illnesses are preventable and need to be recognized as a serious workplace health and safety hazard. Establishing a good heat illness prevention plan, ensuring that workers are taking adequate breaks and have access to cool potable water and that they are properly trained on heat illness recognition and treatment can make all the difference between a long productive day at work and a potentially life-threatening medical situation.

Understand How Heat Affects the Body

The human body generally cools itself by sweat evaporation. In high-temperature, high-humidity environments, the body’s natural cooling system can become overpowered. In addition to normal exposure to the sun, workers can be affected by heavy clothing and personal protective equipment, strenuous work and other factors.

Just like any other illness that can affect the body, heat-related illnesses tend to come in stages. The first stage of heat-related illness is heat cramps. This is typically a result of the body’s natural cooling process of sweating not being able to keep up with the demands of high temperatures and humidity. Muscle spasms can develop in the arms, legs, and stomach areas, making it very painful for the person afflicted. The spasms can occur after long periods of time where the body has been sweating profusely.

Heat exhaustion is a very serious medical condition that can be life threatening if it is not treated in a timely manner. The signs and symptoms of heat exhaustion include dizziness, fatigue, nausea or vomiting, headaches, excessive sweating and an elevated heart rate. A person suffering from heat exhaustion needs to stop work immediately and go to a cooler location to rest. They should also start to drink water immediately. Medical attention should be sought as soon as possible if the person does not start to show signs of improvement.

Heat stroke is the most severe form of heat illness and is considered a medical emergency. Symptoms can include confusion, loss of consciousness, seizures, and very high body temperature in addition to hot, red or flushed skin. It is very important to call for emergency help immediately if you suspect someone has heat stroke.

Develop a Written Heat Safety Plan

A heat illness prevention plan can be developed around the four simple words that OSHA uses for heat illness prevention: Water, Rest and Shade, Training and Emergency Action Plans.

The plan should detail how to monitor temperature, identify rest areas, distribute water, and handle emergencies. In addition, the plan should explain how employees can report heat related illness without fear of reprisal.

Management must go over the plan at the start of hottest part of the year and all employees, new, temporary and subcontracted, should receive the same information as existing employees.

A written plan of action helps establish consistency and ensures that supervisors make the proper decision quickly when conditions change such as on a hot day.

Monitor Weather and Job Site Conditions

You also must recognize that the weather can change quickly. A cool or even cold morning can develop into hot work later in the day. Workers performing outdoor work on surfaces such as pavement, metal or with limited airflow (for example, in confined spaces or near machinery) are at greater risk for heat-related illnesses than those performing work in other environments.

The air temperature and humidity must be monitored by the supervisor to get an accurate assessment of the heat. The heat index is a good indicator of how hot it “feels” outside, but does not account for direct sunlight or heavy clothing that the worker may wear. Also, local heat sources at the job site, such as roofing materials, asphalt, engines, generators and enclosed equipment must be taken into account when assessing the heat.

In addition to tracking general weather, you must also know about heat sources at the job site. The roof covering, pavement, hot engines, generators, air conditioners, and even enclosed equipment all produce heat. The work can be done in the cooler hours of the day, employees can be rotated through tasks that require periods of hard work in the heat, or the task can be rescheduled for a day when the temperatures are expected to be lower.

Plan hot weather work for less intense periods of time during cooler parts of the day. It may be necessary to begin work earlier in the morning and return to camp for the evening or to work alternative shifts.

Provide Reliable Shade and Cooling Areas

A heat safety program must also include relief from the sun. This can be in the form of a physically-located area of shade or by means of a portable or movable shade such as a tent or umbrella. Many jobs can have relief from the sun by use of a covered tractor or similar equipment. Agricultural workers can be protected by a canopy on a tractor or other piece of equipment to help in relief from the sun while working in the field.

It’s usually not enough to rely on permanent shade at an outdoor work site. Instead, use of portable or even temporary shade is usually more effective in providing adequate protection from the sun. Examples of such structures are: tents; umbrellas; covered trailers; and even canopies that can be put on tractors and other agricultural equipment to provide adequate protection from the sun for long hours of work.

Shade needs to match the job. For example, while agricultural workers are to be protected while working in the field, a tractor canopy can provide good protection for these workers while they are operating their equipment.

In addition to providing adequate shade, supervisors may want to consider using fans, misting systems, air-conditioned vehicles, and/or cooled rest trailers on extremely hot days to provide additional relief to workers.

Remember, these relief areas are not limited to break times! They must be available to workers for the entire length of their shift.

Make Water Easy to Access

Make sure workers have ready access to cool, clean drinking water throughout the work shift. This should be located near the work area, and replenished as necessary.

Making small amounts of water available often is more effective than making a large amount of water available and having the worker drink it all before going out to work. Also, the worker should be encouraged to take drinks of water before he or she feels the need to do so because by the time a worker feels the need to drink, he or she may already be dehydrated.

When considering the type of fluid to provide to workers to aid in hydration during long periods of heavy sweating, sports drinks can be effective. However, they are not a substitute for water. Also, be aware of the high amounts of caffeine and sugar found in some energy drinks, and do not assume that they will provide the same level of benefit as other hydration fluids.

Supervisors must also confirm that workers are actually drinking from the provided water. Just because a cooler is on the job site does not mean that workers are consuming enough water to stay hydrated.

Final Thoughts

High temperatures are a predictable part of many outdoor jobs, but heat illness should not be treated as unavoidable. Employers can reduce risk by planning ahead, monitoring conditions, providing shade and water, adjusting workloads, and training workers to respond quickly.

Heat safety precautions are simple. They must be consistent. They must be supported by every level of an organization. When they become part of the routine of the workplace, as they should be, then, and only then, can all be done safely outdoors in the heat of summer.