Why do injuries hurt more in cold weather?

I hurt my knee but it's not healing like most injuries have in the past...?

• The night before last I went to go get my headphones from my office and on the way back walked right into my bed frame. It hurt initially after the impact of my knee hitting the bed frame and I iced it over the past day or so...the thing that concerns me is that it it's taking a while to bruise, it doesn't hurt when I touch it *except occasionally the knee feels sore*, there looks to be a dent in the side of my knee where the side of the knee slopes but it looks deeper then the other knee *although I'm not sure if that might be due to the swelling* and occasionally when I walk on it recently has started feeling kinda numb. It doesn't hurt when I walk on it at all. I'm wondering if I should really go to the doctor *since I don't have medical insurance* or if it will just heal on it's on? Probably most who answer aren't doctors but best suggestions would be appreciated.

• Answer:

  Really... I don't mean to be rude. It isn't rocket science... go see a dr. Pain is your body's way of telling you something is wrong. Listen to it. Edit: You're right dude. Don't go see the dr. Just learn to live with it.