A comprehensive research review by the University of South Australia, analyzing data from 11 studies with 3,177 participants, has examined the effects of cold-water immersion on health and well-being. The study found that cold-water immersion, which involves exposure to water at 10 to 15 degrees Celsius (50 to 59 degrees Fahrenheit), can provide temporary benefits. These include reduced stress levels and improved sleep quality, though many of these effects fade after about 12 hours or within three months.
While some positive outcomes were observed, such as a 29% reduction in sickness absence among regular cold shower users, the researchers noted limited evidence supporting claims about improved immunity and mood. The study revealed that cold-water immersion causes a temporary increase in inflammation, similar to exercise-induced muscle damage, which explains its popularity among athletes despite the short-term inflammatory response. The researchers emphasize that while cold-water immersion shows promise, more long-term studies across diverse populations are needed to fully understand its lasting effects and determine optimal approaches for different individuals.