Beginning July 23, 2024, California's Indoor Heat Illness Prevention regulations apply to most indoor workplaces.  Among other things, the regulations require that employers implement certain indoor heat illness prevention measures when the indoor temperature reaches certain benchmark levels.  Additionally, employers must develop and implement a written indoor heat illness prevention plan (IHIPP) in the language understood by the majority of workers.

Required heat illness prevention measures must be implemented in most cases when indoor temperatures reach 82°F to prevent the risk of employee heat illness, including access and encouragement to partake of free drinking water and cool-down areas.  Additional heat prevention measures, where feasible, are required when the indoor temperature reaches 87 °F.  These measures include cooling down the work area, implementing work-rest schedules, and providing personal heat-protective equipment.  However, in cases in which workers are wearing clothing that restricts heat removal or are working in high radiant heat areas, these additional heat prevention measures will apply at 82°F.

Previously, employee heat illness prevention requirements, including the written prevention plan requirement, applied only to outdoor worksites.  Now, employers may be covered under both the indoor and outdoor regulations if they have both indoor and outdoor workplaces, meaning that the employer must develop and implement both a written indoor and outdoor heat illness prevention plan. 

If employer has both indoor and outdoor workplaces, the IHIPP can be combined with the employer’s outdoor heat prevention plan.  Otherwise, the IHIPP can either be included in the employer’s general Injury and Illness Prevention plan, or it can be a standalone document.  A comparison of indoor and outdoor heat illness prevention requirements and further information regarding indoor and outdoor heat illness prevention requirements can be found here.  

Employers should also keep in mind that workplace violence prevention plans are also required for most California employers.