When you enter a sauna, you can relax, and some people may be fascinated by its charm. On the other hand, it is also said that the risk of "heat shock" that causes stroke and myocardial infarction may increase. We approached researchers who are working to prevent such risks and make it possible to enjoy saunas safely.
Research on how to enjoy saunas safely
Last month, it was held in Tottori Prefecture and was called the "Japan Sauna Society". It was established four years ago with the aim of promoting health and promoting the appropriate use of saunas.
From high school students to researchers, sauna enthusiasts from various walks of life gather.
Associate Professor Takuma Furukawa of Hachinohe National College of Technology is working on research on how to enjoy saunas safely. Mr. Furukawa, who specializes in heat transfer engineering, aims to predict and communicate the occurrence of heat shock in advance.
Hot sauna and cold water bath. It is said that going back and forth between the two has the effect of relaxing the mind and body. On the other hand, changes in blood pressure due to sudden temperature differences can cause "heat shock" and increase the risk of stroke and myocardial infarction.
In the recent sauna boom, shouldn't we be sounding the alarm about the risk of heat shock? Mr. Furukawa wants to make countermeasures.
Associate Professor
Takuma Furukawa, Hachinohe National College of Technology: "In order to pursue 'totoi,' we are moving in the direction of taking a hot sauna room or a very cold water bath, but on the other hand, in that environment, heat shock is likely to occur.
Heat shock: A mechanism that can be noticed in advance
The goal is to create a system that can detect the danger of heat shock in advance simply by measuring the surface temperature of the skin with a wristwatch-type terminal.
Furukawa believes that the temperature difference between the surface temperature of the skin and the inside of the body is the cause of heat shock. For this reason, we are currently collecting data on temperature changes in the skin and the body.
"Then come in."
On this day, experiments were conducted using a sauna room and a cold bath that are actually used.
This is a graph showing the results of the experiment. The blue line is the temperature of the skin. The red line indicates the change in temperature inside the body.
Compared to the skin, it turns out that the temperature in the body rises with a delay. Experiments have confirmed that there is a difference in temperature change between the two.
By using this result, it is possible to infer the temperature of the body from the temperature of the skin.
Furthermore, by relating the results of this experiment with fluctuations in blood pressure, we aim to develop a mechanism to predict heat shock in advance, and aim for joint research with doctors.
Associate Professor
Takuma Furukawa, Hachinohe National College of Technology: "It is said that heat shock is more likely to occur not only in saunas, but also when elderly people move from a warm living room to a cold restroom, so I think this research will be useful to create guidelines for preventing such things."
You can do it right now to prevent heat shock in the sauna.
It will take some time for this mechanism to be put into practical use, so I would like to take a look at what can be done right now to prevent heat shock in saunas.
We interviewed Dr. Yotaka Kato, a physician and representative director of the Japan Society of Sauna.
First of all, in winter, the temperature of the water in the water bath drops, so you need to be especially careful. Exposure to cold water raises blood pressure and increases the likelihood of heat shock.
Instead of taking a cold bath, it is important to sweat in a shower with adjustable water, and even if you do, choose a water temperature that is not too cold, with a temperature of 17 degrees Celsius or higher, and to get your body used to it little by little before entering.
I would like to enjoy it while consulting with my physical condition without overdoing it.