We all want the best for our dogs.
And sometimes we feel bad if we have to put them outside when it's cold.
After all, us humans we like it warm, and we're all grateful for our central heating - so it's natural to think that maybe your dog house should have heating as well.
But don't get out the credit card just yet.
I've seen it happen many times - someone invests in heating for their dog house, only to find that the dog would rather sit outside.
The fact is, we like it much warmer than dogs do.
What's comfortable for us, may be stifling for a dog.
They have that layer of fur that we don't have! Even short-haired breeds are better able to stay warm than humans.
Also, a well-built dog house is designed to be kept warm just with your dog's body heat.
If your dog house is the right size (which means not too big), and is well insulated (wood is naturally insulating, but many dog houses also have cavity insulation), then the odds are your dog will be toasty-warm without any need for heating.
So, if you then add a heater in - well, you've created a little hothouse! The heat has nowhere to go, because the dog house is designed to keep heat in.
Result - one overheated dog.
No wonder he prefers to sit outside! This is often the best way to tell whether your dog house is too warm.
If your dog won't stay in the dog house, then something's wrong, and that something may well be temperature.
So watch your dog before you invest in heating.
Don't assume he needs heating - wait and see if he seems to be feeling the cold.
So when do you need heating? Well, there are two main situations where your dog will probably need a little extra help keeping warm.
One is if the dog is vulnerable to cold.
That means mostly very elderly dogs, and very young puppies.
So if you have a bitch with pups, and they need to stay outside, you may want to get them some heating.
Similarly, sometimes tiny dogs like chihuahuas have a hard time with the cold.
The other is if you live somewhere with an especially cold climate.
A little snow is usually fine, but genuinely freezing temperatures, or cold for very long periods of time, and you may want to consider heating.
However, in these circumstances, you probably don't want to be leaving your dog outside for long periods anyway.
Better to give them access to a garage or basement where they have some protection from the weather.
If you do decide you want to try dog house heating, here are some options:

• Heated mats.
  The dog equivalent of electric blankets, these are heated pads that your dog lies on.
  These are great for protecting him from cold floors.
  
• Ceiling heaters.
  These are boxes which give off heat.
  You place them on the ceiling of the dog house.
  They're not the most efficient way of heating, as heat rises.
  There's also the danger that they get very warm, so you need to make sure that your dog won't bang into them and burn himself.
  
• Heating units.
  These are usually combined heat and air conditioning.
  They're the most expensive option, and you need to install pipes and tubes into your dog house.
  But if you live in a climate which has both really severe heat and really severe cold, then they can be a good option.
  

Before you try dog house heating, do consider the old low-tech options! A pile of straw can keep your dog perfectly cozy.
You just need to remember to change it regularly.