Job safety authorities in California have approved new rules to protect outdoor workers from the potentially deadly effects of heat.

The new regulation strengthens existing protections for farmworkers and extends safeguards to other laborers, including those who transport heavy materials and work in landscaping, construction and oil and gas fields. Shade must be available when the temperature hits 85 degrees, and employers must remind workers to drink water and closely supervise new employees it reaches 95, under the rules adopted by the California Occupational Safety and Health Standards Board.

In 2005, California adopted landmark heat-illness protections for farmworkers. The rules aimed to protect seasonal workers who picked fruit during the hot summer months. But in recent years, hundreds of farm workers have been found with inadequate shade and no water, prompting calls for updated safety standards. In the last five years, 28 workers have died from heat-related health problems, 12 of whom worked in agriculture, the Associated Press reports.

The new rules are set to take effect this fall.