August 2, 2023
by Allison Harper

Updated Heat Protections Rules in Washington Implemented Year-Round Focusing on Shade, Cool-Down Rest Periods and Monitoring of Workers.

On July 17, 2023, new changes went into effect under WAC 296-62-095 and WAC 296-307-097 expanding the existing requirements relating to outdoor heat exposure. These changes are targeted at prevention of heat-related illness and reduction of traumatic injuries for outdoor workers associated with heat exposure. The new rules are implemented outlining the requirements that are in place year-round, which is an important noted change as the previous outdoor heat rules were only in place from May-September of each year.

These rules are pertinent as workers unprepared for outdoor heat have an increased risk for heat-related illnesses including heat exhaustion and life-threatening heat stroke. Heat certainly can make workers more susceptible to other industrial injuries, such as falls and equipment-related injuries. As such, it is important to review the new rules thoroughly and ensure employers are properly planning and preparing to comply with the updated requirements immediately.

Specifically, the updated rules lower the temperature at which action is required to 80°F for most outdoor work (previously the threshold was 89°F) Temperature-based action levels apply to specific portions of the rule such as sufficiently cool drinking water (meaning cool enough to be readily drinkable) and shade and include specifics on when and how much shade must be provided. Per WAC 296-62-09520 (8), shade is defined as “A blockage of direct sunlight. Shade may be provided by any natural or artificial means that does not expose employees to unsafe or unhealthy conditions and that does not deter or discourage access or use. One indicator that blockage is sufficient is when objects do not cast a shadow in the area of blocked sunlight. Shade is not adequate when heat in the area of shade defeats the purpose of shade, which is to allow the body to cool. For example, a car sitting in the sun does not provide acceptable shade to a person sitting in it, unless the car is running with air-conditioning.” For example, providing a pop-up canopy tent would comply as it blocks direct sunlight and allows for air movement.

Workers must also be allowed to take preventative cool-down periods as needed to prevent overheating (different than mandatory cool-down rest periods) Preventative rest periods may happen concurrently with the existing requirement to provide workers an opportunity to drink at least one quart of water each per hour. Employers must follow high-heat procedures that require close observation of workers and mandatory cool-down periods of 10 minutes every two hours when the temperature reaches 90°F, and 15 minutes every hour at 100°F.

The updated permanent rules also add requirements for acclimatization and exposure to high heat. Under these requirements, which address the need to adapt to working in the heat over time, employers must closely observe all workers during heat waves and any worker who is newly assigned to working in the heat or returning from an absence of up to 14 days. However, employers do not have to determine each employee’s personal risk factors during the acclimatization period.

It is also important to note under the updated rules, “work inside vehicle cabs, sheds, and tents or other structures, may be considered an outdoor environment if the environmental factors affecting temperature are not managed by engineering controls.” The new outdoor rules are the first phase of permanent rulemaking efforts for high ambient temperatures in all industries – keep an eye out for the second phase, which will be targeted at ambient heat exposures in indoor workplaces.

Under the rules, employers must also update their outdoor heat exposure safety programs, and train workers and supervisors on the plan and the new requirements. The Department is developing model outdoor heat exposure safety programs and training materials to help employers implement these requirements.

To aid in the understanding, the Department has drafted a Frequently Asked Questions (FAQ) page, Heat Smart.  This will help employers learn more about the updated outdoor heat exposure rules and learn ways to protect workers from heat-related illness.

If you have questions regarding the new heat exposure rules, please feel free to contact me at (503) 595-6106 or

Posted by Allison Harper.