It's really a matter of preference and what you are comfortable with. I write in both(though third person limited is my preferred), and I started out writing omniscient(multiple points of view-often called head hopping), which can be done well, but I've come to think of it as cheating or even lazy. Just my opinion, but you can do the same thing with a single POV, it just requires a little more thought. I sometimes switch POVs within a story(usually only one chapter if I think it's needed), but it would hold for the entire chapter. Third person limited is certainly not colder... remember it still is told from one POV, but there is an observer element to it which can give you more freedom. I find first has more restrictions than third when it comes to storytelling, but first can have a greater impact for some stories I want to tell. We all must tell our stories in our own way. Cheers and good luck in your writing! G