I found my male sim who went on a walk with his dog, suddenly in his swim wear and freezing to death..... there wasn't any water nearby as far as I know and if it's that cold, I highly doubt they would go in. Sent my female sim out with another dog. She was wearing outer wear, but sure enough at some point during the walk she stopped briefly (see red circle in pic), and before continuing on the walk she suddenly changed into swim wear by herself. So peculiar!!! I really hope this outerwear and also this issue will be fixed.
This is after installing Cottage Living, and the lot is 14 Nettle Lane.
