Cat House Heat Lamp. There are some options you might consider though. You can get lower and higher wattages but I felt comfortable with 100 watt.
Once you install the heat lamp into a suitable light socket or a heat clamp fixture your baby chicks goats lambs reptiles spiders cat or dog will stay super warm on a bitter winters night or a chilly spring morning. This temperature should at least be maintained all the time. Compare and combine with various lighting fixtures versions and select how you can adorn the backyard using light.
An infrared heat lamp or heat emitter is highly effective at providing safe heating for your pets in an animal pen chicken coop reptile terrarium or their favorite sleeping area.
Cat looks like a round peg in a square hole not quite the right size feeties stick out. Those heated pads only pull about 12 - 14 watts so very economical electricity wise. DH and DS built an insulated cat house last winter and that is where the reptile bulb now a hound heater was installed. The two exits include removable clear door flaps to protect kitty from the harsh elements of winter.