I got back home -- a few minutes' drive -- and a couple of toes, as well as both the bottom and back of one heel were numb. This is probably due to Raynaud's, but it's no less disconcerting. I took off my shoes and warmed my feet, gradually confirming that everything was OK.
That said, it was a beautiful evening, with a silvery blue-gray light pervading, and a rose-colored light glowing through when the clouds cleared a bit. I actually saw two other trail runners in spite of the single-digit temperatures.
Distance was 4.00 miles, time 1:06 (moving 58:52), elevation gain/loss 913 feet, avg. pace 16:33 (moving 14:43), and best pace 8:59.