Does this mean "My physical temperature is above where it should be" or does it mean "I feel warm due to the ambient temperature or having just done exercise" or both?
In German, Ich bin heiss has other (sexual) connotations and so does je suis chaude un French. Is this sentence strictly body temperature or does it have other meanings as well?
"Varm" has no sexual connotations, so you needn't worry about being misunderstood. ;)
We do use "het/heit" (hot) to describe people as (sexually) attractive, but not in an expression like the German/French that you mention.
Well, you say that in German and French it means "I am gay". In Polish also "I am warm" ("Jestem ciepły") means "I am gay" :D
it doesn't mean 'I'm gay" in French. "Je suis chaud(e)" would mean "I'm ready and willing". In a non-sexual context, "je suis chaud" also means "I'm ready" - a feminine speaker wouldn't say this though.