Reference; https://mbp-japan.com/jijico/articles/32453/
Modified and translated by CFJA
When the Daily High Falls Below 18°C, Turn On the Heating.
Since 2023, summer heat has become increasingly severe. 2024 was even hotter than the previous year, and 2025 brought prolonged periods of extreme heat as well. By late August, temperatures typically begin to cool, but this year the heat persisted. Then, in October, temperatures dropped suddenly.
September and October are often considered the most comfortable months of the year. However, this year the climate transitioned so abruptly that many people felt winter arriving without fully experiencing autumn. Some may have already started using heating.
This moment marks the time to begin cold-weather preparation. Although Autumn Doyō (秋土用) lasts only 18 days, the body requires approximately three weeks to adapt to a new climate. For this reason, mid-October is an ideal time to start taking preventative measures.
During Autumn Doyō, there is a sharp increase in patients presenting with primary complaints such as respiratory symptoms (coughing, sneezing, nasal congestion), digestive issues, and joint pain including lower back and knee pain. When asked about temperature control at home, most report keeping indoor temperatures low. The overwhelming reason given is, “Because I don’t feel cold.”
However, upon physical examination, most of these individuals have cold hands and feet. Many also have cold abdomens, lower backs, hips, and thighs. Very few are warm throughout the body.
According to Japanese data from the Smart Wellness Housing Promotion Survey Committee, research has been conducted on why people fail to perceive cold even when living in cold environments.
(“7th National Survey on the Impact of Housing Insulation on Residents’ Health,” conducted under the Ministry of Land, Infrastructure, Transport and Tourism’s Smart Wellness Housing Promotion Program.)
The findings show that many people living in environments where indoor temperatures fall below 18°C report that they “do not recognize the cold,” “do not feel cold,” or even find it “comfortable.”
Average indoor temperatures by room type were as follows:
- Living room: 17.7°C
- Bedroom: 13.1°C
- Dressing room: 14.5°C (a space characteristic of Japanese housing)
Among these, approximately 30% of people in living rooms, 60% in bedrooms, and 10% in dressing rooms reported not feeling cold.
The committee identified the following groups as being particularly unlikely to perceive cold:
- Older adults and individuals at high risk for cardiovascular disease, including those with obesity
- Kotatsu users (a traditional Japanese heating appliance)
- Residents of warmer regions
Based on many years of clinical experience, I would personally add:
4. Individuals taking long-term medications
5. Users of electrical heating devices such as heated carpets or electric blankets
(commonly used in areas without central heating)
In addition, it has been reported that low bedroom temperatures can contribute to overactive bladder symptoms, increasing nighttime urination and leading to sleep disturbances.
The survey committee concludes that sensory perception of cold cannot be relied upon, and that measuring room temperature objectively is essential. We therefore encourage patients to keep a thermometer at home and routinely measure the temperature of their living spaces. Air-conditioner settings alone are unreliable, as actual room temperatures vary depending on the housing environment.
We recommend paying particular attention to the temperature at approximately one meter above floor level.
The winter indoor temperature guidelines I suggest to my patients are as follows:
- At rest: 26–28°C (relaxing in the living room)
- During meals: 22–25°C (eating in the dining area)
- During activity: 19–21°C (housework, childcare, or work)
- During sleep: 18°C (in the bedroom)
Cold exposure can act as a silent killer. Therefore, when the daily high temperature falls below 18°C, I strongly recommend paying close attention to indoor temperatures and using heating appropriately.
Acupuncture, Moxibustion, and Oketsu (Blood Stasis) Therapy Are Ideal for Treating Health Issues Caused by Temperature Fluctuations.
If you were unable to take appropriate preventive measures during Autumn Doyō (秋土用) and are experiencing health issues caused by temperature fluctuations, we encourage you to consider acupuncture and moxibustion treatment, which are forms of internal–external therapy in Eastern medicine.
For individuals whose bodies are affected by cold, moxibustion therapy is particularly effective. It is one of the most beneficial treatments for those who suffer from chronic cold sensitivity.
For people who continue to feel unwell after undergoing drug therapy (internal medicine) or surgical treatment (external medicine), acupuncture and moxibustion—working from the exterior of the body to influence internal organ function—can be especially effective. We recommend consulting a nearby acupuncture clinic or a medical facility where a licensed acupuncturist is available.
Maintaining proper daily lifestyle habits is essential. In Eastern medicine, this approach is known as Yōjō (養生), or health-nourishing care. Those who wish to learn more are encouraged to refer to our previous blog articles.
For ongoing health management and health promotion, therapeutic exercise and breathing practices are highly effective.