(CBS SF) — The California Division of Occupational Safety and Health has issued its first heat advisory of the year, because temperatures are 15 to 25 degrees above normal across the state this week.

Record-setting temperatures were expected across the Bay Area Wednesday, according KPIX 5 Meteorologist Lawrence Karnow.

Thursday is expected to be the hottest day, with highs near record-setting levels, and interior locations in the 90s.

A strong ridge of high pressure over California will produce the hottest temperatures in the valleys of southern Monterey County.

Temperatures there may reach 100, according to the National Weather Service.

During this heat wave, Cal/OSHA is reminding employers to protect their outdoor employees from heat-related illnesses.

State regulations require basic protections for outdoor workers, including providing fresh water, shaded areas for breaks, and preparing an emergency heat illness prevention plan.

Cal/OSHA officials will be out inspecting agricultural, construction, landscaping and other outdoor worksites throughout this current hot season.