Ok, I don't want to go back and forth, feel free to believe what you want. Do some research, look up actual cases where remains were found in cold temperatures, where they were found in iced over water, in 35 degree rapids, it's out there.
I would like to add however, that there is truth in ideal temperatures, and when working HRD there honestly is not the urgency (there is to an extent for criminal reasons, but not for life), so waiting until conditions are right is preferable. Those conditions are certainly going to increase your odds of success.
I am not a fan of blanket statements, that's my only issue here with the quote made. KWIM?
Beyond thanks, SARX. You rock.