According to the World Health Organization (WHO), 1.5 billion of world population is overweight, of which 500 million people are obese. We are confronted with an “epidemic” of non-communicable diseases, such as type 2 diabetes and cardiovascular diseases associated with obesity. Maintaining health and appropriate body weight is therefore becoming increasingly important, crucial role being played by healthy lifestyles, that is, regular exercise and healthy nutrition. However, we rarely consider that many of us spend as much as 90 percent of our days in buildings, where factors such as air quality, thermal conditions, light and acoustic environment also importantly impact our health and well-being.
The purpose of buildings is to ensure safety and comfort, to protect us from external factors and enable us to be active and in a regulated environment, even when the sun comes down or the temperatures drop. While we are becoming more aware of air pollution and its harmful impacts, we often do not realize that air quality in buildings can sometimes be even worse than outdoor. We first think of carbon dioxide, carbon monoxide, dust, and possibly mold or radon. However, new insights and research on indoor environmental quality show that a healthy indoor environment also includes appropriate thermal environment. Thermal comfort is an optimal exchange of energy between the human body and the environment. Is the most comfortable always the healthiest? Unfortunately, not! For our bodies, a slight thermal discomfort is sometimes healthier; it increases the resistance of our bodies to adverse conditions and accelerates the metabolism.
In the EU Horizon 2020 project MOBISTYLE, partner organizations are developing IT solutions which could change our habits in the field of energy use in buildings, based on personalized information, ICT, and data on energy use, quality of the internal environment, health and lifestyle. Dr Wouter van Marken Lichtenbelt and his colleagues from University of Maastricht, are transforming our knowledge with research on health and well-being. The effects of the thermal environment on health are difficult to research, especially because changes in health or the body occur slowly and because a number of different factors affect our bodies simultaneously. Nevertheless, research findings show that the most common metabolic diseases are also associated with a constantly comfortable thermal environment – for example, 21 degrees Celsius throughout the year.
In their study (Healthy excursions outside the thermal comfort zone), Dr van Marken Lichtenbelt and colleagues found that short and mild “excursions” outside the heat comfort zone can improve metabolism. In addition to beneficial effects on our health, this also means that such temperature training helps to reduce weight because it increases energy consumption in the body. The environment plays a key role in the thermal balance of the body and its surroundings. The human body produces a minimum amount of heat in neutral conditions for maintaining the body temperature, and on the other hand, mild cold can accelerate body metabolism. Our metabolism is influenced both by heat and cold. While most of the past research focuses primarily on the effects of extreme temperatures, very high or very low, researchers at Maastricht University studied the role of milder temperature fluctuations in human metabolism. Research participants were exposed to a ten-day temperature training, with the indoor temperature dropping to 15 degrees Celsius for a certain period of time. This is such a temperature that we do not get shaken up yet, they were exposed to a total of 6 hours a day. Among others, the sensitivity to insulin in patients with type 2 diabetes increased by as much as 43 percent in this period. The results are comparable to those achieved with the best available drugs or therapies with physical activity. The study also showed that short-term exposure to lower temperatures has a beneficial effect on the circulatory system in healthy people, and the first results show that it can also contribute to the strengthening of the immune system.
The effects occur only in the dynamic changing of the indoor temperature, but they show an exceptional potential for improving the health of building occupants, while with properly managed systems we can also lower the use of energy. Thermoregulatory training must of course be part of a healthy lifestyle. Healthy nutrition and exercise are necessary – but given that the heating season is approaching, we can also keep in mind that exposure to a more fresh (working) environment can be beneficial for our bodies at shorter intervals, as long as we are not shivering.