Plot hole: When you see the shot of New York, just before the scene where the apartment lights go out, there are no lights on in the buildings, or car lights in the street, although it is dark. The lights should still be on as there has not been a power outage. (01:28:00)
Plot hole: Dennis Quaid and his companion seem to have no problems staying warm in just a tent while preparing to sleep for the night; they are actually shown with removed layers of clothing while in the tent. Yet the survivors in the library are covered from head to toe in clothing and blankets.
Suggested correction: Jack and Jason are both extremely close to the heat source in the tent when they sleep at night (within a foot or less) and it's also possible the tent is rated for arctic survival, whereas the survivors in the library aren't always close to the only heat source (being the fireplace). Just because you are inside doesn't mean it's automatically warm. Just like in a house or a garage, even with proper insulation the temperature inside can be equal to the temperature outside.