Got a Sleeping Bag RATED TO -50 F but no Sleeping Pad to put under it? Then your sleeping bag MIGHT keep you warm below 32F ... because a sleeping bag is only as good as the Sleeping Pad (or Camping Cot) it's on.
Without agood Sleeping Pads or Camping Cot of some sort, no one in your survival group will be comfortable ... and you won't be warm either. A good Sleeping Pad, or Camping Cot if you're surviving in place will insulate you from ground cold. Don't make the mistake of purchasing a good sleeping bag and a cheap, inadequate Sleeping Pad or Camping Cot to put under it.