There's nothing better on a cold winter day than to walk into a nice toasty house.

But what constitutes the ideal indoor temperature this time of the year is a hotly debated topic.

BestLifeOnline.com turned to an engineer, Varun Kohli, head of sustainability and analytics at BuroHappold Engineering, for his input on the ideal thermostat setting.

His recommendation? 68 degrees.

Now a number that low may come as a big shock to a lot of you who are accustomed to something in the low to mid-70s. Kohli does acknowledge that you may need to bundle up a bit when the furnace isn't cranking out as much warm air, but he says 68 is a much better setting for both health and energy conservation.

Don't believe him?

The National Sleep Foundation is also on the 68-degree bandwagon. They say if you're sleeping in a room that is too hot or too cold, it might end up disrupting your sleep cycle. That claim was backed up by a 2008 study in Sleep Medicine Reviews that found one of the factors that affected people's sleep patterns the most was improper regulation of body temperature.

That's the healthy part for your body. What about the health of your bank account?

The United States Department of Energy says you can save as much as 10 percent on your heating bill if you set your thermostat to 68 while you're awake. They even suggest dropping the temp even lower when you're asleep or away.

What's your ideal number?