This summer was marked by a prolonged heatwave. Warnings about heatstroke were issued from various quarters. The number of deaths attributed to heatstroke appears to have exceeded 1,000. These heatstroke cases occurred more frequently within the home than outside. This reminds us once again that heatstroke is a risk we face. Preventive measures at home include making good use of air conditioning and electric fans, and frequently checking indoor thermometers and hygrometers. Meanwhile, with the arrival of winter, heat shock becomes a hot topic. It is known that heat shock is particularly likely to occur during bathing in winter. Surprisingly, the estimated number of sudden deaths from heat shock-related causes while bathing is approximately 17,000 per year. This means that nearly 20 times as many people die at home as those from heatstroke. Heat shock occurs when blood pressure changes due to sudden temperature changes place a great strain on the body. But there are even more surprising things. Heat shock is more common in warmer regions than in colder ones. It’s rare in Hokkaido, which is considered cold, but common in Honshu, which is considered warm. In Hokkaido, many homes have room temperatures exceeding 20°C. This time, we’ll consider the positive effects of appropriate indoor temperatures on health and work efficiency.
Influenza and COVID-19 epidemics have been ongoing for a long time. What actions should we take? From an epidemiological perspective, this means blocking the infection routes of bacteria and viruses, weakening the toxicity of bacteria, and increasing the body’s resistance (immunity). One option is to boost our immunity. Good sleep is said to be effective in boosting immunity. So, how can we get good sleep? The quality of sleep is greatly affected by temperature and humidity. The risk of heat shock increases in cold hallways, bathrooms, bedrooms, etc. The average winter room temperature in Japan is said to be around 10°C. In the UK, a healthy room temperature of 21°C is considered healthy. In the UK, a room temperature of 10°C in Japan is considered a risk factor for increased blood pressure and cardiovascular disease. Bedrooms are expected to provide a comfortable thermal environment for sleep. People who stay in a room with a temperature difference reportedly take approximately 1,400 fewer steps per day. Conversely, rooms with no temperature difference tend to be more physically active. Increased physical activity promotes the secretion of serotonin, which then becomes melatonin, which promotes sleep at night. Exercise promotes the secretion of serotonin, which ultimately leads to better sleep.
In recent years, research and information dissemination on sleep quality have become increasingly active. Sleep-related topics are also being discussed in the sports world. Dodgers player Ohtani’s emphasis on sleep and his commitment to sleep aids have been in the news. Thanks to research and information on sleep quality, more and more people are becoming particular about their sleep aids. However, before focusing on sleep aids, we should actually consider the thermal environment of the room. To achieve the best possible sleep, we need to pay attention to the thermal environment of the bedroom. Superior thermal performance in a home lead to positive value creation in health and lifestyle. Even if the room temperature doesn’t have to be set at 20°C like in Hokkaido, a minimum of 16°C or higher is required. Maintaining this 16°C temperature requires improved insulation to prevent heat from escaping. Recently, newly constructed homes have improved insulation performance, allowing them to maintain higher room temperatures. The problem is, the older the building, the more disadvantaged it is. As an aside, children in daycare centers that the temperature was maintained at a moderate level took 1.3 to 1.6 times more steps. Children who exercised more frequently also had lower absenteeism and influenza infection rates. It may be necessary to incorporate multiple factors, such as room temperature, health, exercise, sleep, and enjoyment, into homes in the future.
