That's probably a bad idea then. You have to work your way up, or else you could hurt yourself. And an hour feels like way longer when you're running the whole time.
I used to do 2 miles daily (I need to get back into that routine, actually) and one day on a whim I decided to run my usual route twice, for 4 miles. Even with the proper stretching and icing my legs, the next day I could barely walk. And that was just from doubling my distance, even when I was in pretty decent long distance running form. So doing it cold is definitely a bad idea.