Help me heat my milsbo please?!

Hi there. I am trying to figure out the correct way to heat my cabinet. My only heat source is a wood stove or a portable heater. My house is cold all winter. If I use heat mats, do I put them under the plants on each shelf? I hear people saying they use heat mats, but how? I’ve also heard of someone using a ceramic bulb. Do I just put it in a fixture and point it at the shelf. I’m confused. Can’t quite wrap my brain around it. Help?!