Fluid Temperature has No Effect on Hydration

April 28, 2007 at 12:53 pm 15 comments

We reach for a ice-cold beverages on a hot summer day to rehydrate ourselves in the sweltering sun. Frozen water bottles and ice coolers are used to avoid warm drinks, which seem to evaporate once they hit your mouth.

Contrary to the practice of cooling or warming liquids to relieve your thirst, this study shows that temperature has no actual effect on hydration. Fluids administered to infants at body temperature (37°C) versus room temperature (23°C) were equally effective at hydration. This was the same case in both rotating and bolus (all at once) oral rehydration methods.

However, colder fluids pass throgh your body quicker than warm fluids, giving the perception they are better for hydration. This is not necessarily the case. Additionally, your body experiences a temperature cooling when filled with a colder liquid which feels more refreshing on a hot day. However, when it comes to thirst, colder or warmer drinks will quench it just the same.

Pizarro, D. T., Posada, G. S., Levine, M. M., Nalin, D. R., & Mohls, E. V. (1987). Comparison of Efficacy of Oral Rehydration Fluids Administered at 37°C or 23°C. Journal of Tropical Pediatrics, 33(1), 48-51.


Entry filed under: Fluids, Hydration, Temperature.

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15 Comments Add your own

  • 1. Timmy Jose  |  May 22, 2007 at 2:30 am

    Doesn’t take an Einstein to figure that out now. Does it?!?

  • 2. mike  |  May 24, 2007 at 1:03 pm

    I’m fairly certain I, and most people, have preferred cold water on a hot day because it helps cool you, not because there is any perceived improvement in speed of hydration.

  • 3. audrey  |  June 19, 2007 at 9:16 am

    sure, it takes an Einstein to figure that out. I read the opposite, that cold water is better for hydration, in one of those wellness brochures from my doctor. it sounded fishy.

    I’m going to start reaching for lukewarm water on hot summer days.

  • 4. Bri-Lee  |  August 3, 2007 at 3:49 pm

    You would be 100% correct “Fluid Temperature has no effect on hydration”. However, I am sorry to say, mike (regarding: ‘preferred cold water on a hot day because it helps you cool you’), that is incorrect. Drinking cold water causes your body to work harder, to warm up the cold water, to digest it. As a result, you will not cool down but the contrary. Furthermore, if you drink something warm such as tea, hot chocolate (my favorite), or coffee, it will cause you body to sweat, hence cool you down. But I encourage you to research this, because I am sure you will not take my word for it, you seem like ‘fairly certain’ individual.

    • 5. J  |  October 5, 2014 at 11:29 am

      Bri,Did it not occur to you that if you sweat, then you are becoming MORE dehydrated? Does it make sense to heat up your body, in order to sweat and cool it down? Cool water cools your body down so it doesn’t have to work so hard and use water to do so. My source is a book I read for olympic training many years ago authored by a PhD scientist. What’s your source? YOU?

  • 6. Patrick Bristow  |  October 16, 2007 at 7:04 pm

    I have to say I agree with many of the other commentors… does anyone actually drink warmer or cooler fluids with the hope it hydrates them better? I just drink cold water ’cause it feels good (and warm cider ’cause that’s just how cider is meant to be drunk).

    To Bri-Lee: I once saw a chemist break down the numbers for how much ice you would have to eat to lose a pound of fat (loosely related to what you’re talking about)… the numbers are astonishing. You can drink all the cold water you want for a year… you’ll gain all the calories back by chewing one stick of juicy fruit :)

  • 7. Chad Haering  |  August 20, 2008 at 1:25 pm

    While warm water may hydrate you just as well as cold water, a study from the US Army Research Institute of Environmental Medicine proved that cold water is more palatable. Therefore, under VOLUNTARY hydration, people tend to drink more cold water than warm water, thus staying more hydrated. Consumption of flavored water was favorable compared to unflavored warm water.

    Szlyk, P. C., Sils, I. V., Francesconi, R. P., Hubbard, R.W., Armstrong, L. E., “Palatability of Drinking Water: Effects on Voluntary Dehydration,” USARIEM, March 1998.

  • 8. mzhuddles  |  January 5, 2010 at 7:34 pm

    I actually prefer drinking cold water during the summer and warm water during the winter. Drinking a cup of warm water during the winter actually helps me keep from drinking lots of hot chocolate which are like covert calories to me as I’m just trying to keep warm!

    And curiosity killed the cat…. cold v. hot? it’s like asking “how should i sleep at night?” even though we all need sleep to function just as every person needs water. Sometimes it’s just fun to ask and learn.

  • 9. Amaechi celestine  |  October 18, 2010 at 5:38 am

    I still want to know about what will be use to substitude water.

  • 10. asdf  |  July 29, 2011 at 11:49 am

    Um.. ever drink something really cold indoors and then you start to feel cold?

    Ever drink something hot and then you begin to feel warm?

    If you’re sweating.. and you drink something really cold that makes you feel cooler.. you will stop sweating and losing liquids.. allowing you to sustain your hydration longer.

  • 11. Blake Gillen  |  August 18, 2011 at 1:56 am

    This is either taken out of context or vastly misleading. The study was done on INFANTS and compared 23°C and 37°C (73°F and 99°F). This is room temperature versus body temperature. Nothing to do with hydration in adults when exercising, nor is it anything to do with warm versus cold water in relation to hydration.

    There is a lot of conflicting information, though to be honest, instinctively when dehydrated, most people prefer cold water. There are arguments that cold water passes through your stomach and reaches your intestine faster ergo faster absorption and it lowers core temperature, there are also arguments that because it passes through your stomach so fast you absorb less, though a basic knowledge of anatomy would indicate that it is your small intestine that absorbs water.

    “The stomach has three mechanical tasks. First, it stores the swallowed food and liquid. To do this, the muscle of the upper part of the stomach relaxes to accept large volumes of swallowed material. The second job is to mix up the food, liquid, and digestive juice produced by the stomach. The lower part of the stomach mixes these materials by its muscle action. The third task of the stomach is to empty its contents slowly into the small intestine.”

    I’m no ‘Einstein’ but logic would seem to dictate that since cold water passes through the stomach faster it would be absorbed (by the small intestine) into your body, rehydrating you more quickly.


  • 12. Blake Gillen  |  August 18, 2011 at 1:59 am

    Oh, just found this too… seems a little more comprehensive.

  • 13. NISM  |  September 15, 2012 at 2:00 am

    Thank you for sharing………this post..

  • 14. Fear Of Calling  |  November 14, 2012 at 6:10 pm

    What a stuff of un-ambiguity and preserveness of precious familiarity regarding unpredicted emotions.

  • 15. erikafrose  |  August 17, 2016 at 6:26 am

    Reblogged this on Waterlogged iPhone App and commented:
    This makes sense. I personally prefer room temperature beverages no mater what time of year. ~Erika


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