Protect Yourself From Heat Disorders

Heat disorders indoors: preventive measures

Factors contributing to heat disorders

  • Humidity
  • Lack of a breeze
  • No use of air-conditioner
The Individual
  • General health condition
  • The person's physical health and level of fatigue
  • Lack of sleep
  • The degree to which the person is acclimated to the heat
  • Clothing, etc.
  • Use air-conditioners or fans judiciously
  • Monitor the temperature in your room
  • Improve the ventilation in your room
  • Be sure to rehydrate appropriately
  • Wear cool clothing

Source: Ministry of the Environment, Environmental Policy Bureau, Environmental Health Department, Environmental Health and Safety Division. "Do You Know About Heat disorders?"

Care is needed in areas of the building where heat and humidity accumulate

Rooms containing washers and/or dryers can stay hot for some time, and these areas are also humid. Care should be taken to not spend long periods of time in such spaces. The second (or top) floor of a house can retain heat and humidity that has been generated during the day. If bedrooms are on the second (or top) floor of a house, the windows should be opened, or they should be air-conditioned.

Beware of dehydration after bathing

Around 800ml of water is lost by bathing (based on taking a 41℃ bath for 15 minutes, then resting for 30 minutes)
Due to this dehydration, there is a danger of heat disorders, so it is important to rehydrate before and after bathing.

You may become dehydrated without realizing it

In general, a person loses water through breathing and the skin. This is called insensible perspiration* and it happens without us noticing it. Therefore, it is necessary to rehydrate even if you haven't been sweating.

  • *In the case of a person who weighs 60kg, in a room that is kept at 28℃, approximately 900ml per day is lost. This increases by about 15% when body temperature rises by 1 degree.

Rehydrate regularly even when indoors

It may be difficult to feel thirsty indoor. Even if you do not feel thirsty, try to rehydrate appropriately. Especially the elderly people are concerned about going to the toilets too often and they sometimes refrain from taking enough liquid, which needs to be taken into account.

Lack of sleep and sweating while sleeping also have an impact

Sweating while sleeping can result in a person losing the equivalent of a cup's worth of water. If the person can't sleep because of the heat, that will make them even weaker.

Tea and beer do not hydrate the body

Tea and alcohol have a diuretic effect, resulting in water loss and therefore not being suitable for rehydration. In addition, because sweat contains a lot of electrolytes, such as sodium (salt), rehydrating with water alone is insufficient to prevent heat disorders. A person should rehydrate with a 0.1% to 0.2% table salt solution, sports drink, or oral rehydration solution.

Preventive measures for different situations