California heat illness requirements

Plain-English outdoor, indoor, and wildfire smoke thresholds employers search for under Cal/OSHA T8 3395, 3396, and 5141.1.

California runs three separate heat and smoke standards, and which one applies depends on whether the site is outdoor or indoor. Outdoor work follows T8 3395 on plain air temperature, indoor work follows T8 3396 on temperature and heat index, and wildfire smoke follows T8 5141.1 on AQI for PM2.5 everywhere. A site is never covered by both 3395 and 3396 at once, so getting the site kind right is the single decision that drives every duty below.

Takeaways

Three standards, and the one that applies to your site

Outdoor heat under T8 3395

Indoor heat under T8 3396

Wildfire smoke under T8 5141.1

The 14-day watch on new and returning workers

Frequently asked questions

All guides | Start 14-day trial | Sample packet