Question: I recently purchased a new business, and some of my employees work outside for extended periods of time.  Are there any special steps I need to take to protect them when the weather is hot?

Answer:  Yes, California employers are required to prepare to protect outdoor workers from heat illness. California’s heat illness prevention standard applies to all outdoor places of employment, and additional high heat procedures are imposed on employers in the agriculture, construction, landscaping, oil and gas extraction, and transportation of heavy materials industries.  Heat illness may occur when an employee’s body temperature control system cannot maintain an acceptable temperature. While the body usually cools itself by sweating, high temperatures and humidity prevent the body from efficiently releasing heat so body temperature can rise quickly, causing numerous medical symptoms.

The heat illness prevention standard requires employers to closely observe outdoor workers during a “heat wave,” defined as any day in which the predicted high temperature for the day will be at least 80 degrees and at least ten degrees higher than the average high daily temperature in the preceding five days. Employees who are newly assigned to a high heat area must be closely observed by a supervisor for the first 14 days of employment.

Employers with outdoor workers must take the following steps to prevent heat illness:

  • Develop and implement a Heat Illness Prevention Plan.  The Plan must be in writing in both English and the language understood by the majority of the employees.  The Plan must contain:
    • Procedures for providing water and access to shade.
    • A description of high heat procedures to be implemented when the temperature equals or exceeds 95 degrees.
    • Emergency response procedures that ensure effective communication to contact a supervisor or medical services, and for responding to signs or symptoms of heat illness.
  • Provide training to employees and supervisors before employees begin work that is reasonably anticipated to result in exposure to the risk of heat illness.
  • Provide drinking water that is fresh, pure, suitably cool, free of charge, and close to work areas so that each worker can drink at least 1 quart per hour.  Employers should encourage frequent drinking of water.
  • Encourage workers to protect themselves from overheating by taking cool-down rest periods in the shade for at least five minutes when they feel the need to do so. When temperatures reach 95 degrees or above, employers in agriculture, construction, landscaping, oil and gas extraction, and non-air-conditioned transportation must ensure that employees take a minimum ten-minute net preventative cool-down rest period every two hours.
  • Provide proper shade when temperatures exceed 80 degrees by maintaining one or more areas with shade that are either open to the air or provided with ventilation or cooling. The amount of shade must be sufficient to accommodate the number of employees on recovery or rest periods, so that they can sit in a normal posture fully in the shade without having to be in physical contact with each other. Workers have the right to request and be provided shade to cool off at any time.

Cal/OSHA’s Heat Illness Prevention website contains details on the heat illness prevention requirements and training and can be accessed at  Cal/OSHA also has a Health Illness Prevention e-tool with sample procedures for heat illness prevention at