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Use the OSHA-NIOSH Heat Safety Tool App to help plan outdoor work activities based on how hot it feels throughout the day.

Protect your family and coworkers from skin cancer!

During the hot season the current flag status can be found at 

WGBT Index for NAFEC

Heat related illness includes: heat rash, cramps, exhaustion and stroke.  These illnesses are a real danger to people not accustomed to the stress of hot weather exercise. The Wet-Bulb Globe Temperature Index (WBGT) takes into account four variables: air temperature, humidity, radiant heat and air movement.  Please advise all personnel on the location of the flag poles are located in front of the Station Gym, Front Security Gate, and Ops Security Gate. 

WBGT Index(F)  Flag Color       Intensity of Physical Exercise
         NAVMED P-5010 CH 3

Less than


      White Extremely intense physical exertion may precipitate heat exhaustion or heat stroke, therefore, caution should be taken.
 80-84        Green Discretion required in planning heavy exercise for unseasoned personnel. This is a marginal heat stress limit for all personnel.
  85-87        Yellow Strenuous exercise and activity (e.g., close order drill) should be curtailed for new and unseasoned personnel during the first 3 weeks of heat exposure. 
  88-89         Red  Strenuous exercise curtailed for all personnel with less than 12 weeks training in hot weather.

  90 and


       Black  Physical training and strenuous exercise suspended for all personnel (excludes operational commitment not for training purposes).

Work/rest regimes of permissible Heat Exposure Threshold Limit Values, as recommended by the American Conference of Governmental Industrial Hygienist handbook, "Threshold Limit Values and Biological Exposure Indices", are illustrated below for a normal 8-hour workday. Percentages are for each work hour. Temperatures are listed as WBGT values in Fahrenheit, not to be confused with actual air temperatures in Fahrenheit.

 Work Rest Regime      Light  Moderate   Heavy    Flag
Continuous Work       86 F   80.1 F   77 F  
75% Work/25% Rest       87.1F   82.4 F 78.6 F Yellow
 50% Work/50% Rest         88.5F   84.9 F 82.2 F  Red
25% Work/75% Rest     90 F   88 F  86 F Black

Contact your local Environmental Prevention Medicine Unit (EPMU) for related weather readings. Call the Industrial Hygienist at extension 4377, 4311 or 4304.


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