First, don't panic. Keep breathing when you feel the pain or start to worry. Worry and stress have a way of increasing muscle tension, which won't help you out. Having said that, let's look at what the latest research has to say.
Experts advise a few days of rest after the initial injury, then activity and gentle exercise. A recent study from the United States Spine and Sport Foundation in California looked at the effects of heat and exercise together.
They used low-level heat wrap therapy along with a specific program of exercise. The results were very good. Patients had less pain and more function, returning to their pre-injury level of activity within a week. Heat and exercise together worked much better than either one alone.
Light-weight disposable heat wraps are available at department and drug stores. They are activated by exposure to the air and give constant low-levels of heat for up to eight hours. They are self-sticking so you can keep active and moving.