Most space heaters turn off when they get knocked over, I would check that, if you have some bricks to stack around them to keep the cat from knocking them over and you should get some residual heat off them too.

When it warms up to -8 we usually go swimming up here in Maine. lol. Actually I saw a couple of guys walking out onto the lake this morning at 7:00 am this morning and it was -6 with a strong wind coming out of the North. I dont get it but they looked happy.