Steam/smoke coming from under hood and a weird smoke smell inside car

So this might be hard to explain so hopefully I don't confuse anyone. So now that it is cold and everything I have been using my heater more. The other day when it snowed I of course used it but when I got home I noticed what I thought was smoke coming from under the hood, so I went to tell my dad but he said it was steam and that my car was over heating, he then put coolant in my car. But I don't think that is what it was unless my thermostat is wrong because according to that my car was about 208 like it usually is. Well on top of that the next day I started getting this smoke type smell inside my car and even when you get out of the car you can still smell it...but when I turned my heat off the smell pretty much went away. This morning when I got to work again the smell outside of the car and steam/smoke coming under the hood. I have no idea what the problem is. Does anyone have any suggestions or anything? Let me know please. Thanks in advance for your help