Cal/OSHA recently reminded employers of their obligation to prevent worker heat illness, outdoors and indoors. With temperatures rising into the 90s and 100s in some locations, such measures are necessary to prevent serious injury.

Heat illnesses are potentially fatal. The two most serious are: heat stroke (e.g., red, hot dry skin, high body temperature, muscle twitching, confusion, fainting, convulsions, unconsciousness); and heat exhaustion (e.g., dizziness, headache, sweaty skin, fast heartbeat, nausea, vomiting, weakness, and/or cramps). Heat rash and heat cramps can also occur.

Decency and concern for their employees should be sufficient to cause employers to take appropriately protective measures. If that is not enough, Cal/OSHA dictates employer duties to prevent heat illness with serious repercussions for non-compliance.

For outdoor areas, employers must take measures starting at 80° F, increasing to "high heat" precautions at 95°F for agriculture, construction, landscaping, oil and gas extraction, and loading and unloading of heavy industrial and commercial products.

Employers must protect outdoor and indoor workers with:

• Water - Provide free, fresh, pure, suitably cool drinking water so workers can drink at least 1 quart per hour and encourage them to do so.

• Training - Train all employees and supervisors on preventing heat illness (so they can avoid it and know what to do if it occurs).

• Rest - Encourage cool-down rests in the shade for at least five minutes when workers need to protect themselves from overheating, without waiting until they feel sick to cool down.

• Shade - Provide shade outdoors when temperatures exceed 80 degrees; indoors, provide a room below 82 degrees. Workers must be allowed such a cool-off area whenever they feel they need it.

• Plan - Have an effective written heat illness prevention plan for indoor and outdoor workers, including emergency response procedures.

These protections and others are outlined in Cal/OSHA's Comparison of Indoor and Outdoor Heat Illness Prevention Standards chart, also showing where indoor and outdoor protections differ. Cal/OSHA also provides heat illness prevention training materials such as its Heat Illness Prevention tool and its Indoor Heat Illness FAQs.

Take-Away:

Employers must take heat illness prevention obligations seriously, ensuring they provide such protections to all employees and supervisors working in high heat conditions.

For further information, please contact Tim Bowles, Cindy Bamforth or Helena Kobrin.

See also:

• Solid Foundation: Workplace Policy Handbook and Forms for 2025 (June 20, 2025)
• In the Hot Seat: Employer Pays Big for Ignoring Extreme Conditions (January 10, 2025)
• Chill Skill: California's New Indoor Heat Rules July 23, 2024 (August 2, 2024)

Helena Kobrin
July 3, 2025