Cold showers may improve well-being and reduce sick leave. They may also cut energy use and carbon dioxide emissions, a Swiss study suggests.
For her doctoral thesis, Dr. Lena Glaser of the University of Basel examined how willing people are to adopt habits that benefit both the climate and their health when those habits can be easily added to daily life. She tested the idea using cold showers.
“When people talk about changing their behavior to protect the climate, the discussion usually focuses on transportation, diet or recycling. But in those areas, radical solutions, such as banning flights or serving only vegetarian meals in workplace cafeterias, often meet with resistance. Some people even see them as an attempt to control their lifestyle, even though they know that flying contributes to climate change and that eating meat has negative consequences for both the environment and health,” the expert explains.
“If we want people to change their behavior, we need a more empathetic approach. Taking a cold shower is not particularly pleasant, but it’s a small change. After all, we take a shower anyway,” she says.
She notes that water temperature and water use rarely come up in discussions about protecting the climate, even though changing shower habits could have an environmental impact comparable to that of recycling.
For the study, the researcher invited 719 people between the ages of 18 and 65. They were asked to take showers at the lowest possible water temperature for 12 weeks. Participants had to be in good health and have no previous habit of taking cold showers.
Many participants dropped out during the first two weeks, which, the researcher explains, suggests that people get used to the change gradually. Over time, the remaining participants reported feeling better, both mentally and physically.
This subjectively felt improvement was also reflected in fewer sick days: Participants had, on average, 31% fewer days of work absence due to illness than people in the control group.
The volunteers also said they were proud of adopting a new, healthy habit that required some discipline. The researcher explains that cold showers can also save money. First, people usually spend less time under them, so they use less water. They also save energy because the water does not have to be heated.
For a shower that uses 45 liters of water, lowering the temperature from 40 to 15 degrees Celsius (104 to 59 degrees Fahrenheit) saves as much as 1.3 kWh of energy. That means lower energy bills and a measurable reduction in CO2 emissions.
According to the experiment’s author, over the 12 weeks of the study, participants cut their CO2 emissions by an average of 15 kg per person. That is roughly equivalent to the emissions from driving a car 100 kilometers (about 62 miles).
“When people see personal benefits from changing their behavior, and at the same time don’t feel that they have to give something up or are losing something, they are more motivated to stick with the change,” says Glaser.
The researcher did not check whether participants continued to take cold showers after the project ended. It is also unclear how environmentally conscious they were in other areas of life, or whether they made up for the discomfort of cold showers with other pleasures. Such behavior could limit or even completely cancel out the environmental benefits.
Glaser adds that even small changes in water temperature can have positive effects, so there is no need to opt immediately for extreme solutions. “If we force ourselves to give up all comforts and pleasures, sooner or later it will take a toll on our well-being and mental health. And being sick isn’t good for the environment either,” she says.
She therefore points out that at home, it is enough to set the water to a temperature that a person finds acceptable that day. “It’s important to listen to your body and pay attention to how you feel at the moment. Sometimes, though, it’s worth pushing your own limits a bit,” she concludes.
Marek Matacz (PAP)
