[.....What's with asking if heat doesn't affect him? Wouldn't "bother" be a better word to use?]
Well, what kind of butler would I be, if I allowed myself to be bothered [see? this is a human response. so human] by the weather, or requested to be let up on my duties for the sake of frivolities?
[Translation: no one cuts him any slack and he's not allowed any beachtime fun. Poor Sebastian ):]
Mm, it does seem quite the perfect set-up for enjoying the company of others. You are used to cooler weather, then?