Researchers from Umeå University have conducted a study examining the risks of serious cardiac rhythm disturbances, or arrhythmias, associated with cold bathing among young and healthy individuals. The findings suggest that the risk is low for brief immersions, provided that participants are healthy and do not immerse their heads in water. More than 50 healthy teenagers from Umeå took part in the study, where they submerged their faces in 10-degree Celsius water indoors, with some also engaging in full-body immersions in ice water for up to one minute.

During the experiments, participants were equipped with ECG monitors and heart rate devices. It was found that harmless extra heartbeats were common during both full-body and facial immersions. However, more pronounced heart rhythm disturbances were observed with facial immersion, leading to a decrease in heart rate. The study indicates that an ice-cold water dip activates the sympathetic nervous system, which elevates the heart rate, while submerging the head triggers the parasympathetic nervous system, which slows it down. When both these systems are activated simultaneously, the risk of arrhythmia can increase.

These findings lend support to established guidelines for cold bathing: it is recommended to bathe for a short duration and to avoid immersing one’s head in cold water. This research could have implications for individuals partaking in cold water activities, emphasizing the need for awareness and careful adherence to health guidelines to minimize potential cardiovascular risks.