is it okay to put a heating pad underneath the corrugated plastic of a C&C cage??

Question

im trying to find ways to help keep my guinea pigs warmer, would putting a heating pad underneath the corrugated plastic even work, i wouldnt put the heat so high that it would melt the plastic
also if that wont work can i use one of those heated rock things that you put in reptile cages, and just put it in their cage so they have a warm spot to sleep by
if neither of these ideas work can you suggest something else?

please dont say turn up the heat, i have a thermometer in my room and it says that it is 20 degrees Celcius(i think that is 70 degrees farenheit) but it still feels sort of cold

my guinea pigs are 9 week old abbyssians if that helps at all

Answer 1

I don't think a heater would work. The plastic would probably melt or catch fire. You could fill a sock with rice, sew up the end and zap it in the microwave for a bit. If you wanted more of a pad, just make one as big as you want. Just watch so they don't chew it too much. Providing them with a house could also help them be warmer. Or a small dog bed