Scorching temperatures spell danger in many parts of the country that are under heat advisories. The heat index has risen to over 100 degrees in Texas, Ohio, Oklahoma, and several other states.

This can lead to dehydration, a potentially deadly condition. According to Today, you can do a skin pinch test to see if you are dehydrated and need more fluids. A verified TikTok user identified as Dr. Karan Raj, a surgical physician from the U.K, posted a video of how to perform the test.

You simply grab some skin on one of your finger knuckles and pinch for a moment. If you are well hydrated, when you release the skin, it will return to its original position. But if you are dehydrated, the skin loses its elasticity and will stay in a tented-up position, says Raj.

Samantha Cassetty, a New York-based registered dietitian, advises holding the skin for about three seconds before letting go and it should snap into place within a couple of seconds. The expert warns that this method to gauge hydration levels in the body is not foolproof.

"One issue with this test is that older people have less elastic skin, so when pinched, it remains tented for a more extended period of time. This doesn't necessarily indicate dehydration," she told Today.

The skin pinch test is also not reliable in children. Lack of skin turgor, or elasticity, can also be caused by certain medical conditions, Cassetty said.

The skin pinch test is considered to be a preliminary measure, say studies. There are other methods to do a self-check. According to the Cleveland Clinic, when you are healthy and hydrated, your urine should fall somewhere between colorless and the color of light straw and honey.

When you don't consume enough fluids, your urine becomes more concentrated and turns a darker yellow or amber color.

When too much water is lost from the body, its organs, cells, and tissues fail to function. If dehydration isn't corrected immediately, it could cause shock.

The general recommendation is that women need 11.5 cups of fluid daily and men need 15.5 cups, says the Mayo Clinic. But this amount varies for individuals on the go, athletes, and people exposed to high temperatures.

"If there's a chance you're even slightly dehydrated, it's a good idea to drink more fluids. If you are significantly dehydrated, you might benefit from an electrolyte drink designed to help you absorb and retain fluid better than drinking water," notes Cassetty.