Could a brief blast of cold water mean fewer days off sick? Research involving 719 adults found an association between regular cold showers and fewer reported sick days, though it does not show that cold water prevents illness.
Researchers led by psychologist Lena Glaser analyzed three trials conducted in Switzerland from 2019 to 2024. Participants tracked their shower habits and reported illness and sickness-related absences over 12 weeks. The findings were presented in a doctoral dissertation at the University of Basel.
Participants who took cold showers at least 70 percent of the time reported 26 percent fewer days feeling ill and 31 percent fewer days off work because of sickness than those who showered cold less often or not at all. The cold-shower routines involved two to five minutes under the coldest available water setting.
What the results do--and don't--show
The study relied on participants' own reports, and the results do not establish that cold showers stopped infections. Regular users did not show statistically significant improvements in overall physical well-being or skin health. They did report modest gains in psychological well-being and energy.
Earlier research has also found fewer sickness-related absences among people who ended warm showers with a short cold rinse, but evidence that cold exposure strengthens immunity remains inconclusive. It is also possible that people who maintain the routine differ from those who stop in ways that affect their health.
Sticking with the habit proved challenging: only 37 percent of participants in a related analysis completed the full 12 weeks. The researchers found that motivational videos and a confidence-building program did not improve adherence.
A small habit with a wider footprint
Using less heated water may also reduce household energy consumption. The researchers estimated that participants avoided about 15 kilograms of carbon dioxide emissions each over the 12-week period.
Sudden cold exposure can put strain on the cardiovascular system. People with cardiovascular conditions or Raynaud's phenomenon should seek medical advice before trying it; others who are curious can lower the water temperature gradually. Further research will be needed to determine whether cold showers offer reliable health benefits, while their potential energy savings may make the habit worth studying from a sustainability perspective.
