Thanks, all; it's comforting to know this happens to others, too. (Woo-hoo! I'm normal!! Or as normal as some of you! )

Shannon, it happens for whatever length ride I take; today's ride was 25 miles. My "maintenance" rides tend to be in the 11-17 mile range; it happens after those, too. Nothing else causes this (though I don't do any other exercise to speak of). How much I eat/drink depends on whether I'm hungry/whether it's hot out. I had 16 oz of water and food just before today's ride, so didn't eat while on it (but did after) and had 16 oz of water during the ride. It was cool today, so I wasn't sweating buckets as I do in warmer weather; on a hot day, I drink much more. (Pour water over my head, too! )

westtexas, even when it's in the 90s, I'll feel cold after I cool off from the ride! It doesn't have to be cool out for this to happen. And I'm very glad you haven't died yet!

Tulip, I've tried a wicking fabric; still prefer cotton (though I miss the pockets). Hot tea is a great idea! Will have to convince myself to get out from under my blanket. (And I feel okay, thanks! Just cold, though okay with long pants/turtleneck/blanket. Oh, geez. I see my old age and it is... here. )

Velo and jess, no Raynaud's; I googled it, and wow, the hand colors are very impressive! I feel cold all through, not just extremities. jess, I think Bike Writer and I need to join you by that space heater!