rest or push through it?

Woke up with a pretty bad cold this morning (I've been trying to push it off for the past couple of days to no avail). I just tried to start my workout for the day and felt utterly exhausted about 30 minutes into the hour-long DVD. My body feels like it needs a major nap, but I know exercise might help. Should I push through and finish the DVD, do another workout or call it a day and rest?