While I was inflating my rear tire the other day, I've noticed a rusty metal piece stuck in the tire.
Since I'm running tubeless setup, I grabbed a tool to remove the piece out so that the sealant in the tire can seal the tire. And then....
As soon as I pulled the nail out, the sealant leaked out for a bit, but it eventually seal the hole.
I don't know how or when the nail got in there, but I'm happy about the fact that I didn't have to install a tube in freezing temperature. :D