Slow 2 at 88 degrees

I ran 2 miles tonight.  Total time 20 minutes.  First mile was 10:17, last one I went faster to complete in 9:43.  My left calf hurt me all day today.  It's just really sore.  I stretched for 10 minutes before running, and that did seem to loosen both legs up a little, but I definitely felt the pain with every step.  I'm not doing anything else until the race.  I hope it isn't too hot Saturday, because these last two nights in the 80 plus degree weather has reinforced in my mind that running when it's hot is not my strong point!