Happiness Is a Warm Blanket
In the dead of winter we start daydreaming about warming ourselves on a far-flung sandy shore. Stiff neck or achy muscles acting up? Give them the muscle equivalent to a warm beach: a heating pad. Heat from a heating pad or hot water bottle wrapped in a towel increases the blood flow to the area where you apply the warmth and helps muscles relax -- in about 30 minutes you'll notice relief from cramps and stiffness.
Alternatively, soaking in a warm bath for about 15 minutes can help ease muscle pain -- add some Epsom salt and help reduce inflammation at the same time.