Frostbite!

I didn't really think anything of it, but when I was back home for Christmas I went out in dress flats really late one very, very cold night. (Think like ten below with strong winds.) My feet got some snow on them but I didn't really pay much attention. The next morning when I got in the shower, I noticed a blackish gray patch on the top of my left foot. I thought maybe I bruised it, but when I touched it, it didn't hurt. Or really have any sensation at all.

Pretty sure it's frostbite. Oh South Dakota, you land of many charms.