I could see the hot water breaking down the oils on the fur and skin and dissipating in the water. On the other hand scent dogs work best at tracking when there is a light rain or mist as the moisture makes it easier for scents to be picked up.
Almost all of my corns will vary their strike based on the temp of their prey. If it's just barely room temp they simply just half heartedly bite it and retract. If the prey is warmer they constrict. They don't expend anymore effort than needed. That typically holds true for all the ones I've raised. I have a few animals that I got as adults and previously had been neglected. They act as if each meal is their last, they hit hard/fast and constrict every time.
Some of my balls prefer their prey a few degrees warmer than others.
My retics I make hunt for their food so they mostly go by scent even though they have pitts.