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Dehydration is more likely in cold weather; here’s why

INDIANAPOLIS (WISH) – Think you’re not at risk for dehydration in the winter? Think again.

According to Purdue University scientist Libby Richards, an associate professor in the School of Nursing, dehydration can be much more dangerous in the cold weather. Why? Because we don’t even realize it’s happening.

Gillis: We’re talking about dehydration. Now, it is wintertime, but dehydration can happen especially when we’re exercising outdoors, let’s say. We feel cold and we might not be sweating beneath all of our layers. But still we can get dehydrated. Can you speak to the importance of not only staying hydrated but also how dehydration occurs specifically during the months? 

Richards: It is possible to get dehydrated in winter just as it is in summer. And it actually could be a little bit easier to get dehydrated in winter for a few reasons. One reason, as you mentioned, is we sweat less and when we do sweat it tends to evaporate faster. So, we are not noticing that sweat cue as “Oh. I’m losing fluids. I need to drink some water.”

In addition, in cold weather, people can actually become less thirsty. We don’t always have the natural cue to drink. And then to make it even more challenging … when it’s cold outside and we breathe we’re losing fluid through our respiratory system. So, even if we’re not being physically active just the act of being outdoors in the wintertime can increase our risk for dehydration, which makes it all the more important to make sure that we are getting an adequate amount of good fluids 

Gillis: So, we don’t get as thirsty, the sweat evaporates more quickly … how does that happen? What’s going on there?

Richards: It’s just that you become warm and it’s cold outside. So, the natural reaction is for the sweat to evaporate. It’s a cooling mechanism for us. But because we don’t have the sweat hanging off of our brow as we do in the summertime, we don’t think about becoming dehydrated. So, the lack of noticing the sweat is what puts people at risk of being dehydrated in the wintertime

Gillis: And I’m thinking about when it’s really cold out and exhale that vapor … that sort of cold air coming out of our lungs. Is that water? Does that lead to dehydration?

Richards: It sure does. So, when the weather is cold outside we are exhaling out fluid. When you see your breath it means that respiratory droplets are coming out of your lungs. We are losing water as we are breathing in cold weather. 

Gillis: Last 30 seconds. Anything else you’d like to add? You have the floor. 

Richards: Absolutely. Because you may not be as thirsty, it is even more important that you are drinking adequate amounts of fluid. We recommend that you drink about half of your body weight in terms of fluid ounces. So, if you’re 150 pounds you need 75 ounces of good fluids every single day. 

For strategies to stay hydrated, click here.

News 8’s medical reporter, Dr. Mary Elizabeth Gillis, D.Ed., is a classically trained medical physiologist and biobehavioral research scientist. She has been a health, medical and science reporter for over 5 years. Her work has been feature in national media outlets. You can follow her on Facebook @DrMaryGillis