Flag Conditions, Based on WBGT readings ONLY

Definitions

For the purpose of flag conditions, essential activities are those basic to the completion of the assigned mission of the Naval Station and tenant commands, they can not be suspended or delayed without a serious effect on mission accomplishment. Leadership must ensure proper acclimatization and implementation of Operational Risk Management(ORM) to ensure mission accomplishment. [COMNAVACTSPAININST 3140.2]
Green Flag (80°-84.9° WBGT)- Utilize discretion in planning heavy exercise for unacclimatized personnel because the environment is at a marginal heat stress limit for all personnel.
  • Heavy exercise for unacclimatized personnel should be conducted with caution and under responsible supervision. Buddy system is recommended.
  • Heavy exercise for acclimated personnel is unrestricted.
  • Drink 1 quart of cool water per hour. Use 75% work and 25% rest for outdoor work (example: 45 minutes work and 15minutes rest). Heat cramps and heat exhaustion possible with continued exposure.

Yellow Flag (85°-87.9° WBGT)- Strenuous exercise and activity must be curtailed or markedly reduced for new and unacclimatized personnel during the first 2 weeks of heat exposure. Heat stress can occur.
  • Strenuous exercise is limited to those acclimated 14 days or longer.
  • Drink 1-2 quarts of cool water per hour. Use a "buddy system" and have teams monitor each other's condition. Use 50% work and 50% rest* (example: 30 minutes work and 30 minutes rest). Heat cramps likely. Heat stroke and heat exhaustion possible with continued exposure.

Red Flag (88°-89.9° WBGT)- Strenuous exercise must be curtailed for all personnel with less than 12 weeks training in hot weather. Heat stress is likely to occur.
  • All physical training should be halted for those who have not become thoroughly acclimated by at least 30 days of physical activity at this temperature. Those who are acclimated may carry on limited activity.
  • Drink 2 quarts of cool water per hour. Use a "buddy system" and have teams monitor each other's condition. Use 25% work and 75% rest (example: 15 minutes work with 45 minutes rest). Heat stroke possible with continued exposure.

Black Flag (>90° WBGT)- Non-Mission essential physical training and strenuous exercise must be suspended for all personnel. Heat stress will occur in most cases.
  • Outdoor work should be limited to critical missions only (requires commander approval). Use 25% work and 75% rest (example: 15 minutes work with 45 minutes rest). Use a "buddy system" and have teams monitor each other's condition. Drink 2 quarts of cool water per hour. Heat stroke likely with continued exposure.