The effect of cold water endurance swimming on core temperature in aspiring English Channel swimmers An Australian group has examined the course of the body core temperature in floats, which have completed a preparatory swimming over 6 hours at a water temperature of around 15-16 ° C. It showed that the body core temperature absorb, regardless of the physique of the swimmers.
Older floats tended to a hypothermia as well as swimmers with a deeper impact frequency while swimming. This work can be found under https://pubmed.ncbi.nlm.nih.gov/26835005/