Imagine a cartoon character who gets so angry that steam starts to blow out of their ears! http://4.bp.blogspot.com/-QtfUCNovLWA/TzRcoZNACII/AAAAAAAABo0/HW6Nlt81hD8/s1600/yosemite_sam.jpg

A related expression is "angry enough to blow one's lid". Both the evoke the image of the head as a pot/kettle of water at full boil, on the verge of exploding

Imagine steam coming out of a boiling kettle. We use this image to describe someone who is getting very angry.

when you speak to a boring person who make you nervous