Water bottles with hot tap water work as well. Roll some hand towels around them and put them near the enclosure. They get about 110 degrees and last quite a while. Just refill them every few hours and you're good to go.
I suggest using a UTH on a thermostat for perminant heat, however. So this doesn't happen again. Or at the very least keep some backup bulbs handy.
I would be using a UTH, but the cage I currently have is cracked on the bottom, so I worry about the cracks worsening if I heat it.