Marilyn Shipman

I've recently discovered this tv series. Watching the tv series for the first time without reading the book(s). I have the 1st 3 books on order and will receive them soon. In the meantime, well, of course, I have questions... I am confused about the book/ tv show's take on vampires. Traditionally, vampires are night creatures - cannot tolerate sun light or they will be burned. So, how can Matthew live in daylight, sleep at night, eat food (other than blood) and drink things (other than blood)? Aren't they supposed to be cold? I understand that he is 1500 years old, so does that age make him immune to sun, food, etc.?