Farting in a sauna. The heat mixes with the methane and hydrogen sulfide to form an acrid hot gas that burns the nostrils. A beef kiln is considered worse than leaving a farting gift in an elevator. Quite embarrassing when a stranger (especially of the opposite sex) enters soon afterwards.
Olaf (in sauna): Prrrp! A beef kiln! Time to go, methinks!
Erika (entering sauna): Oh God Olaf, not again! That gas is making me cry!