Commuting - BF docs, can you shed some light on this?

No, I ain't insane enough to seek medical advice from a message board. I was just wondering why it is when you freeze your extremities to the point you can't feel them anymore, they hurt like hell when you get into the shower even if the water isn't that hot? However, if you let them warm gradually to the same temp in the air, there's no issue.

Thankfully, I've only experienced this phenomenon with fingers and toes (mostly toes)......

Ever turn the lights on in the middle of the night?

I ain't no doc, but my reconin' says that blood that was diverted from surface tissue and extremities to keep the core warm is rushing back (aided by hot water) to cold, constricted vessels, swelling the tissue beyond its ability to stretch.

Either that or its athelete's foot.

legot's explanation is pretty close to the truth. It's not just toes and fingers, if you have someone suffering from hypothermia, unless it's a very mild case rapidly rewarming them could kill them. The body isn't meant to shift gears that quickly. It's similar to how when you rapidly heat & cool metal it becomes brittle and breaks easily.

It's similar to how when you rapidly heat & cool metal it becomes brittle and breaks easily.
Kind of like the way they got rid of the T-1000 in Terminator 2 (except I believe a shotgun blast helped the frozen metal shatter) :D

When I was little, I imagined everything hurt because my blood was so cold, it was like throwing an ice cube in water. Years later, I started to suspect that my fingers and toes weren't quite cold enough to shatter.......

Legot's explanation sounds very sensible to me and definitely fits with my own observations. Do any of the docs think this line of reasoning is out of whack with reality?

There are different pain receptors for different sensations. Pressure, temperature, and injury (cutting/shearing) are the ones that spring to mind immediatly. Making temperature ones really cold and then putting something warm on them will make them report a much larger gradient of temperature than if you let them gradually warm up.

Kind of like riding with traffic reducing a collision speed from riding against traffic.

Next time they feel painful, put some pressure on them. The receptors which report pressure and compression travel to the spine faster than the receptors which report pain and the ones which report injury, so pressure will effectively head them off at the pass ("Head them off at the pass? I hate that cliché!").