Working out, exercising a lot, running or walking – people do all of these things to stay healthy and doing so is especially important in a pandemic. However, beyond just exercise, what is also crucial is hydration. Drinking plenty of fluids during your workout routine is essential for your health, so it is useful to know when you're dehydrated and how much is plenty.

One way to check whether you're dehydrated is a quick skin-pinch test. Pinch the skin over the back of a hand. Skin with normal turgor, or elasticity, will rapidly spring back to its usual position when released. Mild dehydration will cause the skin to be slightly slow in its return to normal.

Time to drink some fluids, in other words.

But there are better indicators that your body needs water. "I'd sooner link (dehydration) to physical symptoms such as listlessness, headache or a dry mouth," says dermatologist Dr. Christoph Liebich.

The reason, he explains, is that skin doesn't react promptly to fluid depletion. "Being a dermatologist, I may of course see that the skin lacks its customary sheen and moistness," he says. "But this is hard for a layperson to judge."

On hot days, Liebich advises drinking more than the recommended minimum of 1.5 liters of water daily. "You can hardly drink too much," he remarks.

Water is also his preferred method of cooling down. He lets cold tap water run over his hands and lower two-thirds of his forearms. "That's the most pleasant way," he says.

When you're outside on hot and sunny days, Liebich says it's best to stay in the shade from 11 a.m. to 4 p.m. Exposing your skin to sunlight before and after, even if you've applied sunscreen, will help your body produce sufficient vitamin D and boost levels of "happiness hormones," he notes.

"Sun protection is essential, because the alternative is skin cancer."