Cal/OSHA is urging employers across California to take steps to prevent heat illnesses as one of the year's first heat waves hits the Bay Area, pushing temperatures above seasonal averages. The agency warns that new employees may need additional protection due to the heat, particularly those who are not yet acclimatised to the high level of heat. Under state heat illness prevention rules, employers must provide workers with water, shade, rest breaks, and maintain written prevention plans and training for supervisors.