National Weather Service Issues “Excessive Heat Watch”; State Officials Issue Heat Illness Prevention Alert

The National Weather Service has issued Special Weather Statements in regards to heat and an Excessive Heat Watch onTuesday, May 13, 2008. Such is the statewide concern over the potential hazards to employee health and well-being posed by this heat wave, state officials from the Divivision of Occupational Safety & Health, Department of Industrial Relations, and the Labor & Workforce Development Agency organized a conference call and issued alerts to employers and other stakeholders.

Although all employers have a duty to provide a safe and healthful working environment for employees, Cal/OSHA regulations now require any employers with outdoor worksites to provide training and have a written program on Heat Illness Prevention. Because of statewide high and possible record-high temperatures expected in the short term, and probably all summer, various California state officials have issued an alert to employers to remind them of the duties to provide Heat Illness training. The regulations, originally issued in 2006, require all employers with outdoor worksites to:

  1. Provide heat illness prevention training to all employees, including supervisors.
  2. Provide enough fresh water so that each employee can drink at least 1 quart per
    hour and encourage them to do so.
  3. Provide access to shade for at least 5 minutes of rest when an employee believes he or she needs a preventative recovery period. They should not wait until they feel sick to do so.
  4. Develop and implement written procedures for complying with the heat illness prevention standard

The Division of Occupational Safety and Health has also provided the following information to help employers comply with the regulations:


Before employees can work outdoors, employers are required to provide them with heat illness prevention training. This mandatory training for supervisors and employees under the new standard includes the following information:

  • Environmental and personal risk factors
  • Employer’s heat illness prevention plan and procedures
  • They need to drink water frequently throughout the day
  • Importance of acclimatization (allowing the body to adjust gradually to the work in high heat)
  • Types of heat illness and the signs and symptoms
  • Necessity of immediately reporting to an employer any signs or symptoms
  • Employer’s procedures for responding to symptoms
  • Employer’s procedures for contacting emergency medical services. This includes alternative modes of transportation
  • Employer’s procedures for emergency communications. This includes the emergency response procedures such as location, local medical services, and communication alternatives.

Adjusting to the heat

One training component for employees on heat illness prevention is the importance of acclimatization, or adjusting to physical activity in hot weather. The body needs time to adapt to increased heat and humidity, especially when one is engaged in heavy physical exertion. Typically, people need four to fourteen days to adjust fully to significant increases in the heat. Cal/OSHA data reveals that most workplace deaths related to heat illness that occurred last year involved new employees who were on the job only one to four days and were unaccustomed to working in hot or humid weather.

While the heat illness prevention standard calls for employers to train employees on the importance of acclimatization, it is up to employers to determine what acclimatization procedures they will use. The best strategy is to allow employees, and especially new ones, to adjust to hot weather by gradually increasing to a full work shift and pace. On very hot days, other good strategies include timing the shift so that more work can be done during the cooler parts of the day, increasing the number of water and rest breaks, and using a “buddy system” so that workers and supervisors can monitor each other. Also, employees should be reminded of the cooling benefits of wearing loose fitting, light-colored clothing and a wide-brimmed hat, when it’s feasible.


Recent safety and health data shows that all the surviving victims of heat illness had access to some shade during work periods, lunch, or at breaks. Under Cal/OSHA’s new standard, an employee working outdoors who wants to cool off must be provided with shade for 5 minutes at a time. Shade for heat illness recovery periods must be accessible to employees at all times. In industries other than agriculture, employers may utilize measures other than shade to provide cooling if they can demonstrate that these alternative measures are at least as effective as shade.

According to the new standard, shade means blockage of direct sunlight. Shade is sufficient when objects do not cast a shadow in the shaded area and there is sufficient space for the employee to be comfortable. Shade is not adequate when the temperature in the shaded area prevents cooling. You must avoid sources of shade such as metal sheds or parked cars that are hot from sitting in the sun. Also, tractors and other machinery do not qualify as sources of shade and have the potential to create an even greater hazard. If you have employees who work outdoors, consider some easy-to-assemble portable sources of shade, such as umbrellas, canopies, or other temporary structures. Buildings, canopies, and trees all can qualify for shade as long as they block the sunlight and are either ventilated or open to air movement.


The third component of the new standard requires an employer to provide employees, working outdoors, one quart of potable, fresh and cool water per person, per hour. In last year’s case studies, Cal/OSHA data revealed drinking water was present at all worksites, even though 78% of those who succumbed to the heat suffered from dehydration. Therefore, it is critical to keep drinking water accessible and remind your workers to drink it frequently.

Written Procedures

The new standard requires an employer’s heat illness prevention procedures to be in writing and made available to employees and to representatives of Cal/OSHA upon request. These written procedures must include:

  • How an employer will comply with the heat illness standard requirements.
  • How to respond to symptoms of possible heat illness, including how emergency medical services will be provided.
  • How to contact emergency medical services, and if necessary, how employees will be transported to a point where they can be reached by an emergency medical service provider.
  • How they will ensure that, in the event of an emergency, clear and precise directions to the work site can and will be provided as needed to emergency responders.
  • Employers are encouraged to integrate their heat illness prevention procedures into their Injury and Illness Prevention Programs (IIPPs). All the elements of the Heat Illness Prevention standard must be implemented to prevent serious illness to your workers. By protecting your employees from heat illness, you promote a healthier and more productive workplace.

To learn more about the shade, water, written procedures and training requirements of the Heat Illness Prevention Standard, visit

Comments are closed.