First, congratulations on starting a new exercise program.
Second, don't use heat on sore muscles! It can just exacerbate the chemical reaction that causes inflammation, making things worse rather than better. Plain old rest is better, ice if you feel like you've strained something. (For a great article on this, see
here.) It's probably time for a rest day.
Third, and this may be small comfort: the first couple of weeks are usually the worst, in terms of post-exercise soreness. After that, you're body starts to become more accustomed to the exercise, and won't get as sore.
(Of course, if your body gets too accustomed to a given workout, it means you're no longer getting as much fitness value out of it as you did when you first started. That's why fitness professionals recommend that you change around your workout, and shake things up when you've hit a plateau... but that may not be for a while, yet.)
be strong //
K