Hi Everyone please chip in if I dont get this right, Sarah Mae I am going to try and explain this to you but if I simplify too much please dont be offended.
There are three different types of nerve cell

1. Autonomic Nerves - these are the ones you dont have any conscious control over - they makes sure your internal organs work eg heart beat, digestion etc

2. Motor Nerves - these respond to signals from your brain that are conscious - ie they do the work that you personally want and they make your muscles contract so you can move your body.

3. Sensory nerves - they sense what is happening in the outside world and send a signal to your Central Nervous System and Brain to let your body know how to respond eg it is getting colder so the sensory nerves send a signal to your brain which in turn sends a signal to your body to contract muscles so that your body moves to put the heating on.

Your condition is effecting the third type of nerves which is why you may feel a burning in your feet when it is cold or your feet could be icy cold when it is really hot. The pain comes as these nerves are sending mixed up messages to the brain which means your brain thinks there is a stimuli hurting your body even although there isnt.
There are long and short nerves which is where the length dependant comes in - and I think the #s refer to specific nerves which have been damaged.

Nerves have a nucleus( this controls the function of the cell) in the main body of the cell and they have a long arm reaching out from the main body(think of it as an exploratory arm which is looking for the external signal) - this arm is the axon and has a protective coat around this called a myelin sheath. - sounds to me as if you have a problem with the axon inside the cell where others have damage to the protective layer outside.

Hope this helps - basically your sensory nerve cells are damaged and sending the wrong signals to the brain so the brain is getting jumbled up messages which means you are getting pain/burning/ice cold - the numbness is coming from cells which have been damaged too much.

Again sorry if this is too basic for you - I am coming to this from a teachers angle rather than a medical background.
Ironically this was my favourite topic to teach - little did I know it was going to control my life so much