I suppose that means that, after all, people taken for a sucker give off a 'sucker aura'.

He radiates happiness around wherever he goes.

Teachers should occasionally let their students blow off some steam.

The fire burned brightly, giving forth a comforting warmth.

That will let you blow off steam.

The roses gave off a nice smell.

It's very important to know how to let off steam, living in this world.