Originally Posted by chief domestic engineer
Nope, no melting of the plastic at all.
The intake holes are below the fire and the hot air - I bet you could put your hand on the side of the drum near the bottom and it would not be all that hot - the lid is rarely too hot to handle and it is probably the hottest part of the outside of the drum. Many have used flexible magnets to cover their draft holes. IIRC they don't like heat very much either. I have used pvc fittings outside of the drum w/o any issues.
That said, something is off with your intake or exhaust holes if you "need" a blower. The only time one might actually be helpful is lighting your coals with a weed burner. I use a tiny blower very successfully - but it is part of my BBQ guru.