I do play with Mods/CC.
That is carpet. I mentioned it's indoors, why would there be snow? And I guess because that sim likes to swim?
I do not believe there is an issue with the house.
Thank you for the information.
I mentioned snow since I have seen times where snow was inside when a room was not sealed or buggy. I mentioned swimwear since there have been times that I have found my sim was cold or worse, even inside with heat on, in (swimwear or) a pool, in particular during 'very cold'/(maybe also blizzard?) conditions outside. Also, as I mentioned, this can happen if the room is not properly sealed.
Personally, I removed the effects of temperature in my game a while back when there were random issues with them freezing, and putting winter clothes on automatically when outside in cold weather. I think this is not an issue now, but I cannot tell you for sure. If you check and the weather is not severe, and the rooms are properly sealed, and the sim is wearing winter clothing and they are still behaving this way, you may want to test without the mods and cc and see if the issue remains. The fact that you said your sims are also 'slipping' inside like they are falling on ice makes me wonder if it's either a non-sealed home (and possibly severe weather) situation or a mod/cc issue.
If this is the only issue you're seeing and you care less about proper weather sensitivity than your Mods/cc, you could see if deactivating their sensitivity to temperature in settings solves the issue for you.
