Fluid Replacement Guidelines for Warm Weather Training

Applies to Average Acclimated Service Member Wearing Hot Weather Uniform
Posted : Monday, January 01, 1900

HEAT
CATEGORY

WBGT
INDEX
DEGREES F

EASY WORK

MODERATE WORK

HARD WORK

WORK/
REST
MIN

WATER
INTAKE
QT/HR

WORK/
REST
MIN

WATER
INTAKE
QT/HR

WORK/
REST
MIN

WATER
INTAKE
QT/HR
   1 78-81.9 NL 1/2 NL 3/4 40/20 3/4
  2
(GREEN)		 82-84.9 NL 1/2 50/10 3/4 30/30 1
  3
(YELLOW)		 85-87.9 NL 3/4 40/20 3/4 30/30 1
  4
(RED)		 88-89.9 NL 3/4 30/30 3/4 20/40 1
  5
(BLACK)		 > 90 50/10 1 20/40 1 10/50 1
  • The work/rest times and fluid replacement volumes will sustain performance and hydration for at least 4 hours of work in the specified heat category. Individual water needs will vary ? 1/4 quart/hour.
  • NL= no limit to work time per hour.
  • Rest means minimal physical activity (sitting or standing) accomplished in shade, if possible.
  • CAUTION: Hourly fluid intake should not exceed 11/4 quarts.
  • Daily fluid intake should not exceed 12 liters.
  • Wearing body armor adds 5° F to WBGT Index.
  • Wearing all MOPP overgarments adds 10° F to WBGT Index.

EASY WORK

MODERATE WORK

HARD WORK
  • Weapon Maintenance
  • Walking hard surface at 2.5 mph, with a 30 pound load
  • Guard Duty
  • Marksmanshp training
  • Drill and cermony

 
  • Walking loose sand at 2.5 mph, no load
  • Walking hard surface at 3.5 mph with a 40 pound load
  • Calisthenics
  • Patrolling
  • Individual movement techniques such as low crawl, high crawl
  • Defensive position construction
  • Walking hard surface at 3.5 mph with a 40 pound load
  • Walking on loose sand at 2.5 mph with load
  • Field assaults

 

Source: FM 21-10 Field Sanitation