You probably pinched a couple of arteries and your hand is swollen. A year ago, when my leg was swollen, it went away in a couple of days. But it's better to see a doctor.
Don't use ice. If you're going to use anything, use heat.
Ice can very easily cause more damage, especially when you don't know for certain what the issue is.
It likely isn't swelling and definitely not carpal tunnel.
Did the arm start hurting or was it staying numb?
It happens often when you sleep, probably just blocked blowflow or some such, it won't be dangerous.