Using a Lötkolben (solder iron) is very common in a hackerspaces with an electronics lab. Sometimes using a non-operational and cold Lötkolben with a young redheaded girl can cause amazing screams, giggle and laughter (in this order or all at once).
h0uz3 once took his famous Ersa TIP260, carried it around at the tip (which was completely cold), ran towards a young redheaded girl, said „Schau mal, ein Lötkolben!“ and touched her bare arm with the cold tip. In anticipation of being burned she screamed and ran away horrified, but laughed a lot after realizing it was acually just a cold solder iron.