Japan is dangerously hot this summer, and dehydration can sneak up on you without warning, so stay safe with this easy tip.

Summer in Japan is almost always hot, but this year it’s on a whole other level. How hot is it? It’s hot to cook a meal on the roof of your car, and also hot enough that one man figured he’d go without clothes for the day as a last-ditch effort to stay cool.

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:
1. Lightly pinch the skin on the back of your hand.
2. Let go.
3. Count how long it takes for the pinched area to return to its normal appearance.

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.

@snow_belltree goes on to remind us that this is just one possible symptom of dehydration, and that even if your skin returns to normal in under two seconds, there’s still a chance that you’re becoming dehydrated, so listening to your body (especially if it’s telling you it needs fluids and shade) is always the most important thing to do. Still, with its easily measurable criteria, the skin pinch test provides easier-to-understand results than subjective dehydration symptoms such as “dry mouth” or “heavy sweating,” so it’s something to try periodically this summer as you explore Japan (a country in which, remember, you’re almost never far from a vending machine or convenience store stocked with cold drinks).

Source: Twitter/@snow_belltree via Jin

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