can i leave my lab puppies outside in their doghouse in winter time

hello to all animal lovers .i live in BC canada ..and winter time is approaching here ..i bought a couple of lab puppies this year. this is my first year with any kind of pet. i made really good insulated doghouse in my backyard. but still i m worrying about them in coming winter time. some of my family members dont want them to bring inside .so please suggest me if i need to warm up their house with a heater.i m afraid coz its made up of wood and i m not sure if sudden change from cold to hot might make them sick or not ..(bcoz they can come outside their doghouse anytime in night.)

so please suggest !!

Yes, as long as they are old enough to be alone.

You said it was a really good, insulated doghouse, and yet they can come in and out as they like, so I assume you have a little doggie door that will keep out drafts and wind when they are either inside or out.

Labs can take a LOT of could weather. Again, as long as they are at least a few months old.

Depending on where in BC you are, winters could get brutal, and their little body heat may not be enough to protect them.

Heater is the tough part. Don't use a kerosene heater, or any other heater that gives off carbon monoxide.

You might run an electric wire out there for a small heater, just for supplemental heat, and keep it turned on low. The problem with this, is that some dogs, especially labs, like to chew on electric wires, so place the wires so they can't reach to chew through them. Also, place the heater in a space that they cannot "mark their territory". Ouch.