Modified and translated by CFJA
6. The effect of heating devices on sleep
People feel cold when the temperature falls more than 10°C below our body temperature. To maintain our body temperature, we will wrap ourselves in clothing and take warm food into our bodies. When we are active and thinking, a temperature of around 18°C is appropriate, but when the temperature drops below 15°C, we crave warmer food. A typical example is “fire”. Making a fire and staying inside a building is the basic way people spend the winter. However, modern humans are active anywhere and anytime regardless of the temperature. This is probably due to the wonderful heating equipment that mankind has created, and the fact that we have acquired the techniques of protection against the cold.
Now we modern people have had civilized materials since birth, are we able to properly use fire for heating purposes? Do you think that when it’s cold, you can appropriately warm yourself by sitting by the fire all the time? Have you ever heard that “if you spend too much time by the fire at night, you will wet the bed”? When the body is cold, a fire warms the body, but when the body is warm, the skin pore is much open to allow the heat to escape easily. When the ambient temperature is low, the body is more susceptible to cold.
Also, the surface not exposed to the fire will have a temperature difference, so you will always feel cold somewhere. So you apply a fire on the front and back as if you were grilling a fish. The longer you are exposed to the fire, the more fatigued your body becomes. If the body is strongly exposed to cold at such times, children can wet the bed. Adults may wake up during sleep with the need to go to the washroom. Continuous exposure to fire can lead to physical fatigue and consequent cooling of the body. When a person is exposed to sustained heat, the body feels that functioning heat production is unnecessary and stops producing heat.
You particularly have to pay attention to ways of using electric blankets, electric carpets and other items that are indirect contact with the skin and have a temperature that is not variable. They lose body heat while you sleep, making everyone who uses them more susceptible to catching a cold. Electric, gas and oil heaters, air conditioners, etc. can control the temperature, but there is another problem. This means that the room becomes drier, weakening the respiratory system and making it easier to catch colds. In the past, kettles and pots were placed on top of the stove to release steam, but this is rarely done in urban areas due to modern housing conditions. Sleeping with the air conditioning on can be dangerous. It increases the risk of asthma attacks and pneumonia. It is best not to sleep with the air conditioning on unless you are in a very cold climate.
Underfloor heating with hot water or warm air, as in the Korean ondol, is ideal as it gently warms the whole room. Although less common in Western living environments, if people have the habit of sitting or sleeping directly on the floor, this can make the body more vulnerable to illness. Sitting on cushions or using chairs or beds etc. should be considered.
People who are really cold at night and cannot sleep should use the hot water bottle. Place two of these, one is at the placing of your lower back, and the other at your feet, half an hour before you get into your duvet. Remove them when you get into your duvet and you will feel warm on your lower back and feet. You will sleep comfortably. If you have a strong cold and your feet get very cold, it is a good idea to keep the hot water bottle at your feet 50cm away. The temperature of the hot water bottle decreases at night as the ambient temperature drops. They are an ideal heating device as they do not lose body heat. However, it takes a bit of time and effort to prepare, and many people tend to use electric products because of the hassle involved. Recently, the microwavable heating pad, which is heated quickly and hassle-freely, has been developed. Those who can afford it are recommended to use them.