Proteja a los Trabajadores del Calor Extremo. (Spanish version)

Be Heat Smart! Your Outdoor Heat Safety Program

Every year from May 1 through September, employers in Washington State are required to take steps to protect employees working outdoors from heat illness.

Physically demanding work, heavy clothing, and dehydration can put even the healthiest workers at higher risk for serious heat illness like debilitating heat exhaustion and life-threatening heat stroke.

Heat exhaustion can make workers more susceptible to falls, equipment-related injuries, and other on-the-job safety hazards.

Prevention is the best approach to protect workers. Follow safety requirements in applicable rules and use the resources on this page to plan, prepare, and train for prevention.


Additional Emergency Requirements In Effect June 15 through Sept 29, 2022

In addition to existing outdoor heat safety requirements, L&I has adopted emergency requirements that specify:

  • Water must be suitably cool for drinking.
  • Adequate shade (or alternatives).
  • Workers are encouraged and allowed to take paid, preventative cool down rest periods so they don’t overheat.
  • Paid, mandatory cool down rest periods of 10 minutes every 2 hours when temperatures are 89°F or hotter.
  • A method for supervisors and employees communicate about and observe signs and symptoms of heat illness when temperatures are 89°F or hotter.
  • Training workers and supervisors regarding emergency requirements.

See the Questions & Answers tab to help understand the new emergency requirements.

Stay tuned for updated resources to help you update your safety training and safety program to meet the emergency requirements.

The existing rule continues requires employer to:

  • Create an Outdoor Heat Exposure Prevention Plan (Spanish) as part of your required Accident Prevention Program.
  • Provide annual training to employees and supervisors on symptoms of outdoor heat exposure and policies in place to prevent heat-related illness.
  • Increase the amount of water available to employees and providing more opportunity for workers to drink it on days when temperatures require preventive measures.
  • Be prepared to respond appropriately to any employee with symptoms of heat-related illness.

Specific Rules on Outdoor Heat Exposure

L&I is conducting rulemaking on Ambient Heat Exposure. See the "Meetings and Timeline" section for upcoming meetings and ways to provide your feedback on this rulemaking project.

Training & Resources

Accident Prevention Program (APP)

If your business has workers who work outside during May through September, you may also need to document your safety plan. You can use this template:

Training Resources and Other Information

When using any of the follow training resources, be sure to discuss the specific conditions and safety precautions to follow for each worksite.

Training Courses

Additional Training and Information Resources

Search Safety & Health topics for "Outdoor Heat" to find more resources.

Questions & Answers

Other Languages Available

This content is available in the following languages:


Q: When must employers take action to prevent heat-related illnesses?

A: In the rule, employers must take steps to prevent heat- related illnesses when outdoor temperatures reach:

  • 52° F – Workers wearing non-breathable clothing
  • 77° F – Workers wearing double-layer woven clothing
  • 89° F – Regardless of clothing type

Q: Who is required to follow the requirements?

A: Updated requirements apply to the same employers covered previously by outdoor heat rules: Agricultural, construction, and other employers with employees performing work outdoors for more than 15 minutes in a 60-minute period.

The emergency Outdoor Heat Exposure rules take effect June 15 through September 29, 2022.

To read outdoor heat rules and find resources for planning, training, etc., visit

Q: Who determines the outdoor temperature?

A: Employers are responsible for monitoring the temperature at the work site throughout the workday, unless they decide to fully implement all requirements in the rule. Temperature records are not required.


Q: When do employees have to provide water to outdoor workers?

A: Employers are required to provide drinking water no matter the outdoor temperature. 

When the temperature reaches any action level specified in the rule, such as 89 degrees, employers must provide and make readily accessible a sufficient amount of “suitably cool” drinking water to allow workers to drink at least one quart each per hour.

Other rules, like those for the construction industry or agriculture, require access to drinking water separate from this rule and are still in effect in addition to these standards. 

Q: What temperature is “suitably cool”?

A: Although there is no specific temperature listed in the rules, 50–60 degrees is recommended.

Cool-Down Rest Periods

Q: How often are rest periods required?

A: Employers must ensure employees take mandatory preventative cool-down rest periods of at least 10 minutes every two hours when temperatures reach 89 degrees.

In addition to mandatory rest periods, , employees must be encouraged and allowed to take a preventative cool-down rest period when the temperature reaches any action level specified in the rule and they feel the need to protect themselves from overheating.

Q: Does a lunch break count?

A: Yes. Any meal or rest period already required by labor standards in WAC 296-126-092/WAC 296-131-0202 can double as a cool-down rest period.

Q: Are employers required to pay employees during these periods?

A: Yes, except when taken during a meal period.

Agricultural employees paid on a piece-rate basis must be separately compensated for rest breaks and piece-rate down time.

Q: Can cool-down rest periods take place outside of shade?

A: Yes, but the employer must ensure the employees have sufficient means (e.g., air-conditioned areas, misting stations) to reduce body temperature during cool-down rest periods.


Q: When is shade required?

A: Shade, or another sufficient means for cooling down, must be provided at all times for employees when necessary to prevent or recover from heat illness.

Q: What kind of shade is acceptable?

A: Acceptable shade blocks direct sunlight to the degree that shadows aren’t cast under it and it must allow the body to cool off. Shade may be provided by natural or artificial means (e.g., dense tree canopies or tent-like canopies).

In addition, shade must be provided in a way that does not expose employees using it to unsafe or unhealthy conditions or deter or discourage access or use.

Q: How much shade do worksites need?

A: Employers should take into account the crew size and work conditions at each jobsite when determining how much shade to provide.

Shade must be located as close as feasible to work areas and spacious enough to accommodate the number of employees who are on a break at any point in time.

Q: Can employees use a vehicle for shade?

A: Shade isn’t acceptable when heat in the area of shade defeats the purpose — to allow the body to cool.

For example, a vehicle sitting in the sun may block direct sunlight for occupants inside, but would not provide acceptable shade unless it is running with the air-conditioning on.

Employers cannot require employees to use personal vehicles for shade.

Q: Are there alternative methods for cooling down besides shade?

A: Yes. Temperature controlled environments like air-conditioned trailers or misting stations are acceptable alternatives to shade.

Identify and Respond

Q: What should an employer do before an employee suffers from heat illness?

A: Employers are responsible for monitoring the outdoor temperature, observing employees for potential heat-related illness, and having a plan to respond appropriately.

Employers may choose to use phones or radios to monitor and keep in touch with employees working alone. They could also implement a mandatory buddy system where workers team up to watch out for each other.

When a worker shows signs and symptoms of heat-related illness, the employer should relieve the worker from duty, provide shade or other sufficient means to cool down, and monitor the worker to determine whether medical attention is necessary.

Having an established plan for obtaining emergency medical services that is known by all is key. Time is critical

Plan and Train

Q: What are the training requirements and procedures the outdoor heat exposure?

A: All employers must have a written Accident Prevention Program (APP) that includes outdoor heat exposure safety information and procedures.

Workers and supervisors must be trained before working in the heat and annually after that.

Visit L&I’s Be Heat Smart web page for complete details of the rules and additional steps employers and workers can take to prevent heat-related illnesses.

Need help with your Outdoor Heat Exposure Program or Accident Prevention Program? 

Contact an L&I Safety & Health consultant near you. We offer no-charge services and can answer questions you may have.