December 2020 - last edited December 2020
I can duplicate this on PS5 on the Onsen lot only. The chilled moodlet showed up only on the Onsen Lot. My sim then froze to death on a hike while using the Onsen lot as the active lot.
Edit: Tried again with an Iceproof Vampire! (He had a lot of points). He also died.
December 2020
Yes! That's exactly what happens to my vampire Sims. I've decided to not to visit that lot for my vampires until a patch fixes this bug. Every other lot is fine with my vampire Sims and they remain immune to temperatures.
June 2021 - last edited June 2021
My Servo nearly froze to death when visiting the Onsen Bathhouse lot in Snowy Escape. Game version 1.75.125.1030. I was about to file a bug report, then found this thread.
As per the OP, this looks like it's a problem with the Onsen Bathouse lot specifically, so it's not just vampires or servos it's any Sim that's supposed to be immune to temperature extremes.