California employers must protect workers from heat illness both outdoors and indoors. Cal/OSHA’s outdoor heat standard requires free drinking water, shade, cool-down rest, training, emergency procedures and a written heat illness prevention plan, with extra “high-heat” procedures at 95 degrees in certain industries. Since 2024, a separate indoor heat standard requires many employers to measure indoor temperatures and take control measures when they reach specified levels. Employers that fail to comply face citations and, if workers miss required recovery periods, premium pay claims.
Heat waves are becoming more frequent and longer in many parts of California. Here is what employers need to know to stay compliant and keep employees safe.
Who Is Covered
Cal/OSHA, part of the California Department of Industrial Relations, enforces two heat standards in Title 8 of the California Code of Regulations:
- Outdoor places of employment (Section 3395). This covers all outdoor worksites, including agriculture, construction, landscaping, delivery, transportation, security and public works, as well as employees who spend significant time outdoors or in vehicles without air conditioning.
- Indoor places of employment (Section 3396). Adopted in 2024, this standard covers most indoor workplaces, such as warehouses, kitchens, manufacturing facilities and laundries, where indoor temperatures reach the standard’s trigger levels, subject to limited exceptions.
Outdoor Heat Illness Prevention Requirements
Under the outdoor standard, employers must:
- Provide water. Fresh, pure, suitably cool drinking water, free of charge and located as close as practicable to where employees work. Employers must provide enough for each employee to drink at least one quart per hour for the entire shift, and encourage employees to drink it.
- Provide shade. Shade must be available when the temperature exceeds 80 degrees Fahrenheit, large enough for the employees on a rest or meal break. At lower temperatures, employees must have timely access to shade on request.
- Allow cool-down rest. Employees must be allowed and encouraged to take a preventative cool-down rest in the shade when they feel the need to protect themselves from overheating. The rest must last at least five minutes, and the employee should be monitored for symptoms.
- Follow high-heat procedures. In specified industries, including agriculture, construction, landscaping, oil and gas extraction, and certain transportation work, additional procedures apply when the temperature reaches 95 degrees, such as effective communication and observation, pre-shift reminders and, for agricultural employees, mandatory periodic cool-down rest periods.
- Acclimatize workers. New employees and employees during a heat wave must be closely observed, since many heat illnesses occur before workers adapt.
- Plan for emergencies. Employers need procedures for contacting emergency medical services, responding to symptoms and giving clear directions to the worksite.
Indoor Heat Illness Prevention Requirements
The indoor standard uses temperature and heat index triggers. When the indoor temperature reaches the initial trigger, employers must provide water, cool-down areas, cool-down rest, emergency procedures, close observation during acclimatization and training. At a higher threshold, or where employees wear clothing that restricts heat removal or work in high radiant heat areas, employers must also:
- Measure and record temperature or heat index where employees work, and keep those records.
- Implement feasible control measures, starting with engineering controls such as air conditioning, fans, cooling systems and insulation, then administrative controls such as schedule changes and work-rest cycles, and personal protective equipment where appropriate.
Employers should review the regulation’s specific thresholds and exceptions, which include certain short exposures, teleworkers working from a location of their choice and some emergency operations. Remote workers raise their own compliance questions, covered in our post on remote work legalities.
Write a Heat Illness Prevention Plan
Both standards require a written heat illness prevention plan. The plan may be part of the employer’s Injury and Illness Prevention Program. It should:
- Describe procedures for water, shade or cool-down areas, rest, high-heat or control measures, acclimatization and emergency response.
- Be written in English and in the language understood by the majority of employees.
- Be available at the worksite to employees and to Cal/OSHA on request.
Train Employees and Supervisors
All employees who may be exposed to heat, and their supervisors, must be trained before working in conditions that present a risk. Training covers environmental and personal risk factors, the importance of water and rest, acclimatization, common signs and symptoms of heat illness, and how to report symptoms and get emergency help. Supervisors also need training on the employer’s procedures and on how to respond when an employee shows symptoms.
Recovery Periods and Pay
California’s Labor Code treats a cool-down “recovery period” like a rest break. Recovery periods are paid time, and if an employer fails to provide one required by an applicable heat standard, the employee is generally entitled to an additional hour of pay at the regular rate for that workday. These claims are often raised alongside meal and rest break claims, so heat compliance is a wage-and-hour issue as well as a safety issue. See our article on California wage claims.
Retaliation Is Prohibited
Employees have the right to complain about unsafe conditions, request water, shade or rest, and report heat illness without retaliation. California law provides remedies for employees who are disciplined or terminated for raising safety concerns.
Federal Developments
Federal OSHA has proposed a national heat injury and illness prevention rule, but its timing and final content remain uncertain. Federal OSHA can also cite employers under its general duty clause. California employers should treat the Cal/OSHA standards as the controlling requirements and watch for federal changes.
Practical Checklist for Employers
- Identify outdoor work and indoor areas that can get hot.
- Update the written heat illness prevention plan to cover both standards.
- Monitor weather forecasts and, for indoor areas, measure and record temperatures.
- Stock water, shade structures and cool-down areas before the hot season.
- Train new hires before they start and refresh training for existing staff and supervisors.
- Track recovery periods and pay premiums where they are missed.
The Takeaway
Heat illness is preventable, and California’s rules are detailed. Employers with outdoor or warm indoor workplaces should have a current written plan, trained supervisors and the water, shade and cooling measures the standards require in place before the next heat wave.
Frequently Asked Questions
At what temperature must California employers provide shade?
Under Cal/OSHA’s outdoor heat standard, shade must be present when the temperature exceeds 80 degrees Fahrenheit. When it is cooler, employees must have timely access to shade on request.
Does California have an indoor heat standard?
Yes. Cal/OSHA adopted an indoor heat illness prevention standard in 2024. It applies to most indoor workplaces when temperatures reach its trigger levels and requires water, cool-down areas, training, a written plan and, at higher temperatures, measurement and control measures.
Are heat recovery periods paid in California?
Yes. Recovery periods are treated like rest periods and count as paid time. If an employer fails to provide a required recovery period, the employee is generally owed an additional hour of pay at the regular rate for that day.
What are the high-heat procedures?
In certain industries, including agriculture, construction and landscaping, extra procedures apply at 95 degrees, such as observation and communication systems, pre-shift reminders and, for agricultural workers, mandatory periodic cool-down breaks.
How Sutter Law Can Help
Sutter Law advises California employers on employment law and compliance, including written safety programs, wage-and-hour policies and training. Contact us for a free consultation.
This article is general information, not legal advice. Reading it does not create an attorney-client relationship.
