i used a reptile cage i bought years ago that pvc coated wire with a heat lamp right on top and it never melted but that's not to say it isnt possible with a hot enough lamp.
-----
www.myspace.com/ThirdDimensionReptiles

My Kids:
The Scaled:
0.1 Savannah Monitor
2.5 Leopard Geckos
0.1 Green Iguana
1.4 Tokay Geckos
1.1 Bearded Dragons
0.1 Golden Gecko
1.0 Burmese Python
1.0 Het. Albino Ball Python
1.0 Lavender Albino Cali King
1.0 Black RatSnake

The Furred:
0.1 Ferret
1.0 Chinchilla
0.1 Hedgehog
1.0 Sugar Glider
0.1 Rat
1.0 Cat

The Feathered:
1.0 Citron Cockatoo
0.1 Goffins Cockatoo
1.0 Cockatiel