Outdoor Heat Prevention Plan (OHPP)

*This hazard can occur at other times during the year. If so, we will apply all necessary safety measures to prevent heat-related illnesses and injuries.

Environmental heat is more than just temperature. Four factors contribute to heat stress in workers:

1. Air temperature.

2. Humidity - High relative humidity makes it difficult for the body to cool itself through sweating.

3. Radiant heat from sunlight or artificial heat sources, such as furnaces.

4. Air movement - In most situations, wind helps workers cool off.

An environmental heat assessment should account for all of these factors. OSHA recommends the use of wet bulb globe temperature (WBGT) monitor to measure workplace environmental heat.

There are many factors that have a role in creating an occupational heat stress risk to workers. These factors include:

• Environmental conditions (such as air temperature, humidity, sunlight, and air speed), especially on sequential days.

• Presence of heat sources (e.g., hot tar ovens or furnaces) in the work area.

• Level of physical activity, i.e., the workload leading to body heat production.

• Use of clothing or protective gear that can reduce the body’s ability to lose excess heat.

• Individual/personal risk factors.

• Heat sources other than environmental. 

Make use of the following controls to reduce your exposure to heat:

• Air conditioning

• Cooling fans

• Reflective shields to redirect radiant heat

• Misting fans

Follow these practices to reduce your exposure to heat, including water, rest and shade.

• Hydration! Drink an adequate amount of water or electrolyte-containing fluids;

• Try to drink at least one cup (8 ounces) of water/electrolyte fluids every 20 minutes while working in the heat, not just if you are thirsty;

• Keep fluids cool in a cooler or thermos;

• Modify work schedules and activities, particularly for those new to warm environments;

• Take more frequent rest breaks, and take breaks in cooler environment, such as a shady location or air conditioned building or vehicle. The duration of breaks can increase as heat stress rises;

• Skipping breaks in hot conditions is not safe;

• Schedule work during cooler times of day, if possible, such as early morning or late afternoon;

• Adjust and acclimatize to heat conditions, particularly for new workers or those new to heat conditions;

• Minimize manual effort with planning and use of physical/mechanical aids or tools;

• Call for assistance if you have sign of a heat-related illness;

• Administer appropriate first aid to anyone who is developing a heat-related illness; and

• Avoid drinking hot beverages during lunch and afternoon breaks.

Workers can make use of:

• Cooling neck wraps; or

• In extreme heat conditions, consider using vests or jackets with reusable ice packs or cooling packs in pockets.

Several heat-related illnesses can affect workers. Some of the symptoms are non-specific. This means that when a worker is performing physical labor in a warm environment, any unusual symptom can be a sign of overheating.

Heat-Related Illness Symptoms and Signs

Heat stroke

 Confusion

 Slurred speech

 Unconsciousness

 Seizures

 Heavy sweating or hot, dry skin

 Very high body temperature

 Rapid heart rate 

Heat exhaustion

 Fatigue

 Irritability

 Thirst

 Nausea or vomiting

 Dizziness or lightheadedness

 Heavy sweating

 Elevated body temperature or fast heart rate

Heat cramps

 Muscle spasms or pain

 Usually in legs, arms, or trunk

Heat syncope

 Fainting

 Dizziness

Heat rash

 Clusters of red bumps on skin

 Often appears on neck, upper chest, and skin folds

Rhabdomyolysis (muscle breakdown)

 Muscle pain

 Dark urine or reduced urine output

 Weakness

When any of these symptoms is present, promptly provide first aid. Do not try to diagnose which illness is occurring. Diagnosis is often difficult because symptoms of multiple heat-related illnesses can occur together. Time is of the essence. These conditions can worsen quickly and result in fatalities.

When in doubt, cool the worker and call 911.

First aid for heat-related illness involves the following principles:

• Take the affected worker to a cooler area (e.g., shade or air conditioning).

• Cool the worker immediately. Use active cooling techniques such as:

Immerse the worker in cold water or an ice bath. Create the ice bath by placing all of the available ice into a large container with water, standard practice in sports. This is the best method to cool workers rapidly in an emergency.

Remove outer layers of clothing, especially heavy protective clothing.

Place ice or cold wet towels on the head, neck, trunk, armpits, and groin.

Use fans to circulate air around the worker.

Never leave a worker with heat-related illness alone. The illness can rapidly become worse. Stay with the worker.

When in doubt, call 911!

Confusion, slurred speech, or unconsciousness are signs of heat stroke. When these types of symptoms are present, call 911 immediately and cool the worker with ice or cold water until help arrives.

Workers who are new to working in warm environments are at increased risk of heat-related illness. Especially during a worker’s first few days, absolutely all symptoms should be taken seriously. Workers who develop symptoms should be allowed to stop working. They should receive evaluation for possible heat-related illness.

NOTE: Employer should obtain written authorization from medical provider to return to work if DA receives medical attention for heat-related illness.

Some workers handle heat stress less effectively than others. Heat intolerance happens for a variety of reasons. Personal risk factors include:

• Obesity (body mass index ≥ 30 kg/m2)

• Diabetes

• High blood pressure

• Heart disease

• Lower level of physical fitness

• Use of certain medications such as diuretics (water pills) and some psychiatric or blood pressure medicines

• Some medications can result in a worker’s inability to feel heat conditions and/or the inability to sweat, so symptoms of heat stress may not be evident

• Alcohol use

• Use of illicit drugs such as opioids, methamphetamine, or cocaine

The above list is not comprehensive. Other medical conditions can also predispose workers to heat-related illnesses.

Not all workers tolerate heat the same way. When in doubt, workers should talk to their healthcare provider about whether they can work safely in the heat.

The following workers are at increased risk of heat-related illness because of physiological and/or behavioral factors:

• New, temporary, or existing employees who start new work activities:

o in warm or hot environments;

o while wearing additional clothing (e.g., chemical protective clothing); or

o with increased physical activity.

• Workers returning to work environments with potential exposure to heat hazards after an absence of one week or more (for example, returning from any kind of extended leave)

• Workers who continue working through seasonal changes when temperatures first begin to increase in the spring or early summer

• Workers who work on days when the weather is significantly warmer than on previous days (i.e., heat wave)

Acclimatization

To protect new workers from heat-related illness, employers should do the following:

 Schedule new workers to work shorter amounts of time working in the heat, separated by breaks, in heat stress conditions.

 Give new workers more frequent rest breaks.

 Train new workers about heat stress, symptoms of heat-related illness, and the importance of rest and water.

 Monitor new workers closely for any symptoms of heat-related illness.

 Use a buddy system and don’t allow new workers to work alone.

 If new workers talk about or show any symptoms, allow them to stop working. Initiate first aid. Never leave someone alone who is experiencing symptoms!

These increased precautions should last for 1-2 weeks. After that time, new workers should be acclimatized to the heat and can safely work a normal schedule.

• Supervisors should be trained on procedures to implement heat related illness plan, on PPE, and how to respond to heat-related illness or emergency.
• Monitor heat stress taking multiple factors into account and keep workers advised. Consider use of wet globe bulb temperature monitor. (See fn. 1.)
• Determine how to respond when National Weather Service issues a heat advisory or heat warning.
• Determine whether schedules needs adjusting.
• Determine what additional steps may be useful for new workers not acclimated to conditions.
• Train employees on Heat Illness Prevention Plan and to recognize signs of heat illness.
• Ensure first aid is available and accessible, as well as protocol for summoning assistance including medical assistance.
• Take steps if worker shows signs of or symptoms of a heat-related illness, and take immediate action.