Are you prepared for summer's heat?

Those of us who have been living in Japan for some time know that the summers here are no joke, and staying safe during summer has become more important than ever. In saying that, a new study suggests many folks may still be underestimating the risks.

According to a 2026 heatstroke awareness survey conducted by Tiger Corporation, more than 40% of people in Japan wait until just before peak summer in July to begin taking precautions against heatstroke. That's despite the fact that over 40% of respondents said they'd already experienced heatstroke before.

The findings come as Japan introduces the new term “extreme heat days” for days when temperatures exceed 40°C, highlighting growing concern around increasingly severe summers.

One surprising finding was that around 80% of people were hydrating in ways experts consider ineffective, including drinking ice-cold beverages or gulping down large amounts of water at once. Experts involved in the survey instead recommend drinking small amounts regularly throughout the day, aiming for at least 1.5 liters daily, and sipping fluids every 10 minutes in very hot weather.

The survey also found that younger adults were especially vulnerable, with people in their 20s reporting the highest rates of heatstroke experience.

For me the study was a good reminder to hydrate before you feel thirsty, and not to underestimate how quickly the heat can cause health impacts.