I know that when it's hot I need to drink enough water to avoid heat stress, but how much is enough? Is there a ratio between how hot it is and how much water you drink?Answered by Alyx Fier, president, True North LLC, Seattle, WA.
In the course of a day's work in the heat, you may sweat as much as 2-3 gallons, so it's essential that your water intake equals the amount of sweat produced. Unfortunately, you can't depend on thirst alone to let you know when and how much to drink. Usually by the time you feel thirsty you're already dehydrated and having to play catch-up. Instead of waiting until you feel thirsty, you should drink 5-7 ounces of fluids every 15-20 minutes to replenish the necessary fluids in the body. Cool water, as opposed to hot or cold, seems to be the most palatable and easy to drink.
The challenge, then, is to make sure you and other workers have easy access to water, allowing you to drink a cup of water every 15-20 minutes without severely interrupting your work flow. When working from or near a vehicle you can use a large insulated cooler. Another popular option is the use of bottled water sold by the case. When using these water bottles you should consider purchasing an insulated water bottle carrier that attaches to your belt to keep the bottle cool and within easy reach. Another popular alternative is the use of hydration packs containing a reservoir that holds 3 quarts of water. Whatever method you choose, the important thing is that it allows you to consume the right amount of water on a regular basis.
The key to staying hydrated is having the water always at hand. If you put off drinking water until your next break, you may end up in a deficit situation, which will degrade your performance and safety. Remember, if you're feeling thirsty, you're already dehydrated.