I think you’re grossly underestimating the effect of cold shock.
https://scholar.lib.vt.edu/VA-news/VA-Pilot/issues/1995/vp950217/02170571.htm
https://mariovittone.com/2010/10/the-truth-about-cold-water/
https://www.coldwatersafety.org/cold-shock
https://www.instagram.com/p/C7PVf2kvoD0/?igsh=MTBia2Z0ZWk4bmZuNg==