This two-second self-check helps you know if you’re in dehydration danger

Summer in Japan is almost always hot, but this year it’s on a whole other level. But it’s not just laughably hot, but dangerously so. In these conditions, the threat of heat stroke is something you have to be aware of, especially if you’re in Japan on vacation and not acclimated to the weather. What’s worse is that the signs of dehydration can be easy to miss if you’re swept up in the excitement of your visit to Japan, and often by the time symptoms become severe enough to really grab your attention, there’re at the point where they pose a significant health risk.

So to help you avoid having to spend a day laid out recovering in your hotel room (or the hospital), Japanese Twitter user and nurse @snow_belltree has an incredibly simple self-check that literally takes only a few seconds to alert you that you’re suffering from dehydration.

All you have to do is:

That’s it. According to @snow_belltree, the skin’s turgor, or elastic resilience, is a good indicator of your hydration level, and if it takes more than two seconds for your skin to recover, that’s a sign that your body is becoming dried out, and you should get out of the sun and rehydrate as soon as possible.

As an example of how dehydration can sneak up on people, @snow_belltree says that her hospital’s head nurse recently performed spot checks on the facility’s employees, who, as medical professionals, you’d expect to be especially attuned to the need to stay hydrated in periods of intense heat. Nevertheless, three employees failed the skin pinch test, including a nurse and the hospital’s director.