IR #07-40
August 19, 2007

Kate McGuire
Dean Fryer
(415) 703-5050

Cal/OSHA stresses importance of recognizing early symptoms of heat illness

Oakland—Cal/OSHA urges employees working in hot conditions to take precautions since  heat illness is a medical condition that results from the body’s inability to shed heat when high temperatures strike.  Symptoms from over exposure to heat include cramps, exhaustion, fainting and stroke.

“Just a 2ºF increase in normal body temperature can affect mental performance and an increase of 5ºF can result in serious illness or death,” said Len Welsh, acting chief of Cal/OSHA. “It is important for those who work under hot conditions to know how to protect themselves from this under-recognized hazard.”
Cal/OSHA urges that a worker experiencing symptoms such as dizziness, headaches, nausea or muscle spasms should report these to a supervisor or co-worker. Employees who have health problems or a medical condition, such as diabetes, that reduces tolerance to heat, need to be extra vigilant.  Some high blood pressure and anti-inflammatory medications can also increase the risk for heat illness.

Staying hydrated with water is one of the most effective heat illness prevention techniques. Cal/OSHA encourages all employees to drink plenty of water when working in high heat, preferably sipping an 8-ounce cup of water every 15 minutes.  Avoiding alcoholic beverages is recommended since they can dangerously dehydrate the body, especially in hot weather. Sugary drinks such as soda or sports drinks, caffeine from coffee, energy drinks or iced tea are also not recommended. 

It’s also important to take breaks in the shade to cool off, as necessary.  Employers are required to provide a fully-shaded location where workers may rest for at least 5 minutes at a time when needed.  Loose fitting, light colored clothing with long sleeves, and a hat with a large brim give added protection.
Employees who work indoors should take the same precautions as those who work outdoors in extreme heat, and follow similar measures under (section 3203 of Title 8) their employers' Injury and Illness Prevention Program.

With the complete support of Governor Schwarzenegger, in 2005 California became the first state to develop a safety and health regulation to address heat illness. Although the summer of 2006 was a sizzler with a major heat wave that lasted more than 10 days, these new regulations helped reduce outdoor heat-related deaths in the workplace by one-third -- from 12 in 2005 to 8 in 2006.

For more information regarding heat-related illness prevention, free workshops and training materials please visit the Cal/OSHA website at:

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