Right, ActionShark, it's now life-threatening. I feel so stupid to ask, but I don't know what the game description means by this ability Thick Fat, incorporated by Spheal, Sealeo, Walrein, Makuhita, and Hariyama. The game description underlined this ability with "heat-and-cold" protection. It doesn't seem to have an effect on the weather or any moves associated with heat and cold (Sheer Cold, Sunny Day, etc.)
If someone can clarify this description of Thick Fat, I would really appreciate it. And many thanks to those that tried to answer my previous question!