Heatstroke is a medical condition which occurs when you sweat a lot and your body is no longer able to maintain a balance between water and salt or regulate body temperature.
The risk of developing heatstroke increases as temperatures and humidity levels rise.
Typical symptoms of heatstroke include fatigue, dizziness, a headache, profuse sweating, and nausea.
In severe cases, heatstroke can cause a high body temperature, seizures and loss of consciousness. Heatstroke can be fatal. Please seek medical attention immediately.
How to prevent heatstroke
Avoid the heat
・When going outside, avoid direct sunlight and use a parasol or wear a hat. Wear clothing made from a breathable fabric that helps absorb sweat, such as cotton or linen.
・When inside, control the temperature and humidity using an electric fan or air conditioner. Block out direct sunlight from outside using curtains or blinds.
Replenish water and salt lost from sweating
・Make sure to drink plenty of water, even if you do not feel thirsty.
・If you sweat a lot, make sure you get enough salt by drinking sports drinks, etc.
Beat the heat by staying fit and healthy
・Break a sweat through appropriate exercise. Before exercising, make sure to replenish water and salt.
・People are more prone to heatstroke when they lack sleep, are hungover, have a cold, etc., so make sure to take care of yourself and stay healthy.
If you develop heatstroke (first aid)
1. Seek refuge in a cool place, such as the shade or an air-conditioned room.
2. Remove clothing to let out the heat, cool your body and lower your body temperature.
3. Replenish lost water and salt. (Call an ambulance immediately if you are unable to drink water by yourself).
Advice for preventing heatstroke as part of the "new lifestyle" in response to the COVID-19 pandemic
・When wearing a mask during the hot and humid summer season, you will be at an even greater risk of heatstroke than usual. To help reduce the risk of heatstroke when outside, please remove your mask when you are able to do so, ensuring you maintain sufficient distance from others (2 meters at least).
・Please refrain from exercising while wearing a mask. Make sure to drink plenty of water, even if you do not feel thirsty. Take off your mask and rest when you need to, choosing spots where you can maintain a sufficient distance from others.
・Please make sure to take care of and monitor your health on a daily basis, such as by making it a habit to take your temperature. If you feel sick, stay at home and rest.
・Around half of heatstroke patients are people aged 65 years or older. Older adults are more susceptible to heatstroke, as they tend to have difficulty perceiving when they are hot or thirsty. They also tend to be more prone to developing severe symptoms from heatstroke.
・Children are also susceptible to heatstroke, as their ability to regulate their body temperature is not yet fully developed.
・Please look out for children or disabled persons, some of whom may have difficulty in telling others when they feel sick.
Where to inquire
||Public Health Affairs Division, Health and Social Welfare Bureau (*Inquiries in Japanese only)