This response is way late is the game, but I thought I should add my .02 cents of limited knowledge.
Along with the good advice of not to change plugs on a hot engine, you also should back down from the recommended torque settings for plugs (20 Nm in our case), if you are using an "anti-sieze" compound on the plugs. Otherwise, you might over-tighten the plugs and crack 'em when you next go to change 'em.
