An airconditioning engineer died and went to heaven. St Peter couldn't find his name in The Book so, reluctantly, the engineer had to take the elevator to the Other Place.
When he got there, the air was full of brimstone and sulphur and the heat was oppressive. It was ghastly.
So the engineer fitted some exhaust ducts and reverse cycle airconditioning.
A week later, God and Satan were having a chat. God had rung to inform Satan of a technical mistake -- the engineer really was wanted in heaven.
Satan declined, things were much better in Hell since the engineer came along.
"I'll sue!" God yelled down the line.
"Oh yeah?" yelled Satan "And where in heaven are you gonna get a lawyer??"