Winter swimming

Winter swimming is the activity of human swimming during the winter season, typically in outdoor locations, or in unheated pools or lidos. It is done mostly for health benefits. Many winter swimmers swim with standard swimming costumes rather than with wetsuits or other thermal protection.
In colder countries winter swimming may be synonymous with "ice swimming". In Finland, Northern Russia, Norway, Sweden, Denmark, Estonia, Lithuania and Latvia the ice swimming tradition has been connected with the sauna tradition.