National Wildfire Coordinating Group



Dehydration is the result of the body trying to regulate its temperature naturally through sweating. Maintaining body fluids is essential for sweating. You must hydrate before, during, and after work.

  • Studies conducted on wildland firefighters indicate that during fire suppression activities firefighters need to drink a minimum of one quart of fluid each hour of work.
  • Before work, you should take extra fluids to prepare for the heat. Drink one or two cups of water, juice, or a sports drink before work.
  • While working, drink at least one quart of fluid per hour. Drink as much as you can during the lunch break. Water is your greatest need during work in the heat.
  • Hyponatremia (abnormally low concentration of sodium in the blood) as a result of excessive water intake is a potentially life-threatening complication. It can be prevented when hydration is enhanced by electrolytes, through fluids or food containing sodium and potassium.
  • After work, it is important to continue drinking to replace fluid losses. Thirst always underestimates fluid needs, so you should drink more than you think you need.
  • Unacclimatized workers lose more salt in the heat, so they need to pay particular attention to salt replacement.
  • Don’t overdo salt intake. Excessive salt can impair temperature regulation and cause stomach distress, fatigue, and other problems.
  • You can assess your hydration by observing the volume, color, and concentration of your urine. Low volumes of dark, concentrated urine or painful urination indicate a serious need for rehydration. Other signs of dehydration include a rapid heart rate, weakness, excessive fatigue, and dizziness.
  • Rapid loss of several pounds of body weight is a certain sign of dehydration. Rehydrate before returning to work; working in a dehydrated state can lead to serious consequences, including heat stroke, muscle breakdown, and kidney failure.

Discussion Points

  • What are you doing right now to ensure that you are hydrated?


Firefighter Health & Safety
Page Last Modified / Reviewed: 
Sep 2022

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