For me this word «сексуальный» looks and sounds rather funny and literary because I am used to see it only in movies and books. If somebody from my friends say something similar to «Он такой сексуальный» very probably everyone will make fun of him and his silly look. Me thinks that word «hot» cannot be translated exactly. I mean we must just take all possible Russian expressions which are more or less close to «hot» and choose the more appropriate, rather than try to look for more exact translation which is actually never used in normal speech. In other words we don't have to translate English expressions very exactly if this exact translation is never used. Короче, Склифосовский! For me the most appropriate translation is «Он такой симпатичный!». Maybe it doesn't reflect the whole sense of the word «hot» but who cares. Word «симпатичный» is very neutral one. It mean both «beautiful» and (a bit less) «sexually attractive». And it is very popular word. Especially among girls (don't know if I am allowed to use «chicks» here ).