I know that makes some of you shudder, but hey, I grew up swimming in Lake Erie! Staying at the Residence Inn, Mentor, Ohio, up here for a wedding today. The tub is outdoors and not covered so its probably barely over 100 in the tub, but it has 8 great spinner jets, all water, no air, so it doesn't stir up the soap from people's suits. It felt very theraputic after running 2 miles on the treadmill in 16 minutes.