Can you tell me what to do if for the past 4 hours my heart has been racing and my hands are sweating and are freezing! any ideas?

Look for a cause: Rapid heart rate is not a cardiac condition by itself. It usually is a sign of something else. Common causes include fever, pain, anxiety, infection, anemia, overactive thyroid, use of stimulants (caffeine, decongestants) or certain medications. If you cannot identify a cause, you may want to discuss with your local physician about getting an ekg or a 24-hour holter monitor.