You're Probably More Dehydrated In The Winter — A Functional MD Explains Why

As a general rule, the more you sweat, the more you need to hydrate—the issue is sweat has become this psychological marker of Oh, it's time to drink water! and since people tend to sweat more during warmer months, you might unconsciously focus on hydration during the summer.

We should note that, yes, it's still important to hydrate during the summer. But let's revisit that psychological marker we referenced above: Because you might associate sweat with needing to drink more water, in the winter (when you typically don't sweat as much), the urge to drink may get put on the back burner.

However, just because you might not be sweating as much doesn't mean you aren't losing fluids. As Cohen explains, dehydration takes a different route during winter: "It's not because you're outside and sweating so much; it's that indoor environment in the winter we don't take into account." 

You can always, you know, drink more water. The exact number of glasses actually differs for everyone, says Cohen, so it's important for you to find your personal benchmark—she does mention that half your weight in ounces of water is a good place to start, but, again, that can change if you follow a more dehydrating diet or exercise often.