The low temperature last night was about 3 (F). It was 5 (F) when I got up. It was 32 (F) maximum in the shade this afternoon, and it was in the mid 20s (F) when I went out running. The sun was out, the path was dry, and it was a nice, crisp winter day. I didn't run a fartlek at the end of the run. My wakeup HR was down to 54 this morning (55 yesterday morning).