[ Sebastian listens with interest, and it does occur to him that it sounds a bit like what had happened to Ciel to trigger his asthma in the circus. It also gets him to give a resolute nod when Matsui calls the human body odd, since truly, it sounds a great inconvenience. ]

Well, then it is still not so bad as what humans have to deal with, at least. I took a few swims here and while my fingers did feel a bit numb, it was at least nothing so dramatic as looking blue.

[ Would he have stopped if they did? Probably not. Unfortunately, immortals are also cursed with unique brands of stupidity! ]

Feeling warm is very interesting, though. When their senses are so, well, nonsensical, it is perhaps not worth the effort to recreate them so perfectly in the first place. Though clearly with that kind of oddity, their Creator surely must have thought it a funny joke.