I don't have any vents for heat just baseboard heaters which are very old and I don't trust them. I recently bought an oil filled radiator and Storm loves to be in the cat condo which is across from it. Pearl loves snuggling with either Sky or Storm to help her stay warm. Last night was very cold here in CA so even Ziggy wanted to sleep in my warmer bedroom. When I woke up this morning, Storm was wedged in between Pearl & Ziggy. They know how to keep warm. My RB Pepper, also a black cat, used to love sunning himself and he'd get so hot to the touch that I never understood how he could stand the heat.