Feeling unwell from the heat while travelling in Japan?

Heat-related illness is a range of symptoms that occur when heat stops the body's temperature regulation working properly. In Japan it is called 「熱中症」. It can happen not only under the sun but also while resting in a hot, humid room.

Take care too if you're sweating a lot or your hands and feet feel weak. Don't decide on an illness — or decide you're fine — from body temperature or whether you're sweating alone. Check together whether consciousness is clear, whether responses and walking are normal, and whether the person can drink water by themselves. If anything seems off, cool down straight away and ask for help.

Before you leave and while travelling, check the time of issue, the dates and the areas before going out. The heat index is not the same number as the temperature in a weather app or a body temperature. Look at the value for the nearest observation point, but sunshine and wind where you actually are can differ from that point — so watch your surroundings and how you feel too.

The regular heat illness alert, 「熱中症警戒アラート」, is issued when the day's highest WBGT is forecast to reach 33 or above at any point in the target area. That 33 doesn't mean an air temperature of 33°C. Even with no alert, heat-related illness can still occur depending on your condition, your activity and your surroundings.

The 「熱中症特別警戒アラート」 is a special alert meaning dangerously hot weather is expected across several areas and there's a risk of serious harm to health. Stay somewhere cool and check on your companions too. If you're planning to go to an event, check first with the organiser whether it's been cancelled or the date or venue changed, then head out.

On hot days, keep midday outings to a minimum. The Ministry of Health, Labour and Welfare also recommends resting in the shade often and avoiding heat. Indoors too, control the temperature with air-conditioning and drink often.

It's best to cut back first on plans that involve long walks or queueing outdoors. After seeing one place, build in time to rest at your accommodation or somewhere air-conditioned. Even if you shift plans to morning or evening, go by the heat index and how you feel at that time.

Children and older people need extra care, as their ability to regulate body heat differs. Ask your companions whether they're feeling very hot or unwell. If someone has less energy than usual or their responses change, stop what you're doing. If it's a long walk to somewhere you can rest, it's better to shorten the plan.

A cooling shelter is an air-conditioned facility designated by the local government as a place to escape the heat; in Japanese it's called 「クーリングシェルター」. When a special heat illness alert is issued, they're meant to open at set times. For details like the dates and times you can use them, check with the local city or ward office.

Being on the list doesn't mean you can go in right now — check separately. Look at the dates and times in the facility information, and when you arrive ask staff where you can rest. If you're already somewhere air-conditioned, you don't have to move to a cooling shelter.

Rather than walking a long way down hot streets to find a particular facility, ask for help nearby first. If consciousness or walking seems off, or the person can't drink water by themselves, don't spend time searching for facilities — call 119 and cool them down.

Getting indoors doesn't make the heat danger go away. Heat-related illness can happen indoors too, so control the temperature with air-conditioning. If dizziness or headaches continue, get medical care. If someone is unconscious or can't drink water by themselves, call 119.

If the air-conditioning is broken or there's a power cut, ask staff whether there's somewhere cool to rest, whether you can move to another room, and when the air-conditioning might work again. If you need to move to different accommodation, ask the accommodation and the booking company separately about change fees and conditions. Don't assume in advance that you can change rooms or cancel for free.

Even if you've evacuated because of an earthquake or similar, the shelter may have no air-conditioning or it may be unusable in a power cut. If the heat is making you feel unwell, tell staff straight away and ask for help so you can rest somewhere cool.

The Ministry of the Environment's first aid material also recommends resting and taking it easy after you recover. If nausea or vomiting stops you drinking water, or your condition gets worse, call 119.

While recovering, drop plans that involve long walks or waiting outdoors, and decide with your companions first where you can rest. Don't push yourself to travel while unwell just so you don't miss a booked train or flight.

Once you're well enough to move, check separately whether the trains and buses from your accommodation to the station or airport are operating, and whether your booked flight is operating. Transport can be stopped even after you've recovered. If you need to change a booking, ask the operator, airline or booking company how to change it and what it costs. A heat alert doesn't mean every booking can be changed or cancelled for free.

Show someone nearby 「救急車を呼んでください。」 It means “Please call an ambulance.” Tell them the name and location of the place you're at too. In an emergency, don't wait for language support to come on the line — call 119 first.

JNTO's Japan Visitor Hotline is a phone line that guides foreign visitors travelling in Japan when illness or disaster causes difficulties. It's open 24 hours, every day, in Korean, English and Chinese. Within Japan call 050-3816-2787, from overseas call +81-50-3816-2787. If you need an ambulance, call 119 first rather than here.

If it's not an emergency and you're looking for a hospital, choose your area and language in JNTO's Korean medical facility search. Contact the hospital and ask about hours you can be seen, whether they can explain things in the language you want, and whether they can see you now. As a rule JNTO doesn't interpret between patients and hospitals or book on your behalf. Getting guidance in Korean doesn't guarantee interpreting, treatment or booking.