Research is beginning to support the use of cold for health. There are a couple of study links below.
Dr. Lorn Allison
REDUCED REPORTS OF SICKNESS: One study from the Netherlands showed a 29% reduction in sickness absence for (hot-to-) cold shower regimen. The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5025014/
PHYSICAL STRESS TOLERANCE:This Study suggests increase in physical stress tolerance by decreasing uric acid and increasing Glutathione, an antioxidant that keeps all other antioxidants performing at their optimal levels. https://www.ncbi.nlm.nih.gov/pubmed/8063192