I think the older one gets, the lower one's tolerance level is towards the cold.
Cases in point:
We spent the 2004 Christmas holiday visiting my MIL in New York City. The night we arrived, the city received its first snowfall of the season. Needless to say, the kids were ecstatic - they were jumping for joy, sticking their tongues out trying to catch the snowflakes. As for me, I was chilled to the bone...the windchill factor was something like -20 Farenheit...at least it felt like it to me. As I desparately clutched the neck & hood of my parka close to my body to prevent the cold from creeping in, I thought: I don't think I will want to retire in any place that is not tropical or at least, sub-tropical!
Today I went swimming in our pool with my 2 boys. Now, we live in the tropics right on the equator (alright, maybe we are one degree north of the equator, not that it makes much of a difference) & the ambient temp today was something like 33 degrees C, humidity felt like it was in the high 90's if not 100. And yet, when one of my feet went into the pool, the water felt D**N cold (to me, anyway)....cold enough to curl your toes & make other unmentionable parts of the body shrink/pucker/retract.
But my boys? They went right in, initially went "Ooo it's cold" and within seconds (literally) were doing laps & somersaults in the water.
As for me, I stayed seated on the side of the pool with just my legs dipped into the water (up to the knees), to 'allow' my body to gradually accept the sudden change in temperature. Took me at least 10 minutes before I was able to totally submerge myself in the "icy" waters.