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Preventing and Responding to Heat Illness

Elements of Your Written Program and Effective Work Practices


What is in T8CCR 3395?

T8CCR 3395(e) states the following:

(e) High-heat procedures. The employer shall implement high-heat procedures when the temperature equals or exceeds 95 degrees Fahrenheit. These procedures shall include the following to the extent practicable:

(1) Ensuring that effective communication by voice, observation, or electronic means is maintained so that employees at the work site can contact a supervisor when necessary. An electronic device, such as a cell phone or text messaging device, may be used for this purpose only if reception in the area is reliable.

(2) Observing employees for alertness and signs or symptoms of heat illness.

(3) Reminding employees throughout the work shift to drink plenty of water.

(4) Close supervision of a new employee by a supervisor or designee for the first 14 days of the employee's employment by the employer, unless the employee indicates at the time of hire that he or she has been doing similar outdoor work for at least 10 of the past 30 days for 4 or more hours per day.

Best Practices and Warnings

Best Practices

Extra Measures During High Heat

Because of extreme environmental conditions during high heat employees’ physical and mental condition can change even more rapidly into a serious medical condition. The onset of heat illness may be confused with other problems and may not always be obvious before it becomes life-threatening. Therefore, extra measures may be required to prevent and/or respond to heat illness during high heat.

Extra measures during high heat include but are not limited to the following:

  • Communicating Through Meetings
    During high heat a designated person(s) should hold short, frequent meetings (before and during work) with the workers to review the company heat illness prevention procedures, the weather forecast, emergency response and other additional safety measures.
  • Being Extra Vigilant
    During high heat it is necessary to be extra vigilant. Your communication system is (see Effective Communication) especially important to get more frequent feedback from your employees and supervisors in the field. Then, based on the environmental conditions present and the condition of your employees you can more quickly make the appropriate adjustments, communicate them, and put the changes into place before problems arise or become serious. In high heat:
    • Have supervisors and employees watch each other more closely for alertness and any signs or symptoms of heat illness by using your "buddy system".
    • Encourage supervisors and employees to communicate about how they are feeling on a frequent basis.
    • Account for the whereabouts of employees at more frequent intervals throughout the work shift and at the end of the work shift.
  • Changing Work Severity and Duration
    During high heat it may be critical to make adjustments to work activities, see Work Severity and Duration Adjustments.
  • Additional Water Consumption
    • Encourage employees to drink small quantities of water more frequently (i.e., in addition to the four 8-ounce glasses of water, or a total of one quart per hour) throughout the entire work shift to prevent dehydration
    • Have effective replenishment measures in place for the provision of extra drinking water to ensure that supplies are reliable
    • Encourage employees to consult with their doctor on salt and mineral replacement.
    • Encourage workers to also drink water before and after work
  • Drink Only Water
    • Encourage employees to avoid drinking alcohol altogether
    • Encourage employees to choose water over other drinks (e.g., sodas and drinks containing caffeine and sugar) because these other drinks may increase dehydration. Also, if employees choose these other drinks they may drink less water.
  • Shade and Additional Cooling Measures
    Remember that shade is adequate only when it completely blocks the direct sunlight and allows the body to cool. Shade is not adequate when it does not allow the body to cool. In high heat air temperatures in the shade may still be extremely high and not allow the body to cool. For industries other than agriculture, during high heat, you may need to use other alternative cooling measures in addition to shade, (e.g., allowing employees to spend time in air conditioned places). For alternative cooling measures see Shade and Other Cooling Measures.
  • Additional and/or Longer Rest Breaks and Cool Down Rest Periods
    During high heat it is especially important to permit employees the freedom to interrupt work activities to take rest breaks and allow the body to cool. During high heat you may need to allow employees to take more frequent and longer breaks, and more cool down rest periods (see Cool Down Rest Periods). Remember to provide areas for employees to take their breaks and cool down rest periods which are:
    • Readily accessible and in close proximity
    • Open to the air and ventilated or cooled, or in shaded areas
    • Near sufficient supplies of drinking water
  • Changing Meals
    • Encourage employees to eat smaller more frequent meals which reduce the heat the body produces as compared to eating large meals less frequently
    • Encourage employees to choose foods with higher water content such as fruits, vegetables and salads


Remember, even employees who were previously fully acclimatized are at risk for heat illness during high heat. This is because during high heat the body does not have enough time to adjust to a sudden, abnormally high temperature or other extreme conditions.