If its 65w then its PC lighting. (Compact Flouresent aka Power Compact) Not terrible as far as heat goes, but too hot to put them right on the glass without some sort of risk involved.
Small blocks or stand offs will prevent any harm done by direct heat transfer. Many will say they have run PC lighting directly on the glass without issue. Its a once in a blue moon that it could hurt something.
That being said- the moment I tell you to do it, it cue the blue moon to come out and make me look like a sphincter for telling to do so.