Basel study links daily cold showers to fewer work absences

Cold showers were linked to fewer sick days in a University of Basel experiment involving more than 700 people. Over 12 weeks, participants who took a daily cold shower reported feeling unwell on 26% fewer days on average than a control group that continued showering as usual. They were also absent from work 31% less often.

The results, reported by Keystone-SDA on October 29, 2026, put a familiar daily routine at the centre of Swiss research into health and behaviour. Participants were asked to make their showers as cold as their facilities allowed. They had to be in good health and not already take cold showers regularly.

The findings connect a simple household habit with both reported wellbeing and workplace attendance. The experiment also explored how people respond to a behaviour that may feel uncomfortable at first but can be built into an ordinary routine.

The study compared new cold-shower takers with people who kept their usual routines. More than 700 adults aged 18 to 65 took part over 12 weeks. Those in the cold-shower group were asked to use the coldest setting their shower facilities could provide. The control group continued showering as usual.

The participants had to be in good health and could not have been regular cold-shower users before the experiment. That design let the researchers examine people adopting the habit, rather than people already accustomed to it. The measured differences were reported as averages against the control group: cold-shower participants felt unwell on fewer days and missed work less often.

The results came from a University of Basel study announced by the university on a Thursday and reported by Keystone-SDA. The study's duration made it possible to observe how participants responded over several weeks, including the early period when maintaining the new routine proved hardest for some.

The research examined whether a habit becomes easier to adopt when it offers an immediate personal payoff. Psychologist Lena Glaser carried out the work as part of her PhD thesis at the University of Basel. Her broader focus was how people can be encouraged to choose more environmentally friendly behaviour.

Glaser selected cold showers because they can fit into daily life without much effort, while saving energy and money. The initial discomfort was part of the challenge: participants had to alter an established routine and keep doing so over the course of the experiment.

Participants who remained in the study reported an increasing sense of physical and mental wellbeing as it went on. They described feeling more alert and refreshed immediately after showering. A sense of pride in having overcome their reluctance also helped motivate them. The findings therefore paired the reported health and attendance differences with participants' own accounts of what made the cold-water routine rewarding.

The pattern of dropouts suggests that the routine became more manageable for participants who continued. Many people left the experiment during its first two weeks; after that, fewer dropped out. Glaser described the shift as evidence of a habituation effect, saying: “So there does seem to be a habituation effect.”

Those who remained reported rising physical and mental wellbeing over the study period. Feeling alert and refreshed after a shower offered an immediate reward, while pride in pushing past initial reluctance gave participants another reason to continue.

For Swiss households, the study links one low-effort daily change with lower energy use and money savings, as well as reported differences in days feeling unwell and work absences. Its results centre on participants who were initially healthy and not regular cold-shower users. The experiment offers a specific account of how a new habit played out over 12 weeks, from early dropouts to a growing sense of familiarity among those who stayed.