First Aid for Heat Stroke

July 8, 2022

Hokesen Letter, No 228 (English ver.), June 30, 2022
Health Care Center, Tokyo University of Foreign Studies
Yasuhiro Yamauchi, MD, PhD

This year, the rainy season ended earlier than usual, and the rising temperatures across the country are causing days of intense heat, increasing the risk of heat stroke. As for the wearing of masks, which is required in the measures against COVID-19 infection, it is not necessary to wear a mask outdoors except when talking with people at a distance that cannot be secured, and under the hot and humid conditions in summer, it is recommended to "take off one's mask" during outdoor activities in order to prevent heatstroke.

Everyone is at risk of heat stroke depending on environmental conditions such as outside temperature, humidity, and ventilation, physical factors such as poor physical condition (hangover, lack of sleep, etc.), and physical activities such as exercise and work. Therefore, it is important to prevent heat stroke by gradually adjusting the body to the heat, learning the correct prevention methods, and taking care on a regular basis.

Symptoms of heat stroke include dizziness, lightheadedness, yawning, profuse sweating, severe thirst, muscle aches, cramps, headache, vomiting, fatigue, disorientation, impaired limb movement, and high body temperature. If these symptoms occur after being exposed to heat or being in a hot environment, there is a risk of heat stroke.

If you experience any of these symptoms that make you suspect heat stroke, start the first aid as soon as possible.

1. Move to a cooler place

Evacuate to an air-conditioned room, or a well-ventilated indoor.

2. Undress and cool the body

Loosen clothes, replenish moisture and salt. It is also good to wet the skin with a wet towel etc. and fan with a fan or fan, or cool it with ice or ice pack. For the area to be cooled, concentrate on cooling the neck, armpits, and front of the groin on both sides.

(The gel-type sheet does not have the effect of cooling the body when heat is generated.)

In the case of heat stroke due to activities such as sports, cool the whole body by continuing to sprinkle water on the body with a hose as soon as possible. Even when calling the ambulance, it is important to cool down first.

3. Drink frequently and get enough sodium

If you can rehydrate yourself, bring your own cold water and drink it yourself. It is best to replenish salt with an oral rehydration solution or sports drink. If you can't drink yourself, don't force yourself to drink. Since an IV drip is required at the hospital, it is best to urgently transfer to a medical institution.

4. Transfer to a medical institution

If symptoms are strong from the beginning, if you can not hydrate by yourself, if the symptoms do not improve even after treatment, let's transport it to the hospital. When calling an ambulance, start first aid by the time the ambulance arrives.

Please be accompanied by someone who knows the situation at the time of collapse and tell them about the condition at the time of onset.

If you have any questions, please consult with the Health Care Center, TUFS.


Heat illness prevention information.

First Aid for heat illness.

Learning about heat stroke.