Moving here was the first time I ever encountered that sort of evaporative cooling! Getting out of a pool typically just left you *wet*. No big deal to get out and walk around to some other point and reenter. Or, sip a beverage, etc.
Here, getting out was like stepping directly into a FREEZER! A completely unexpected experience. Drove home the principle of evaporative cooling (perspiration, etc.) in a way that a text book could NEVER explain!
Ah! I've only ever seen the spa as a sort of "wading pool" attached to the "real pool" (different pump/filtration/heater). So, you "soak" (heat soak) in the spa, then slide over a little dividing wall into the pool (which is typically much cooler)