I did not have much luck at walmart as far as a light goes, but I did get a good scale so I can weigh her properly.
I had my bf put her box on top of my heating pad until I can get home in a couple hours, that will at least give her a little heat. There are several layers of bedding and dish rags between her and the heating pad so hopefully she will not get too hot. I can put her in my son's bathroom with a space heater if need be.
You can likely find a heat lamp at a home improvement store or tractor supply.
A small space heater in the bathroom should be fine to get the temp in the room to around 80 degrees or so.