The concentration of electrolytes in the body is controlled by a variety of hormones, most of which are manufactured in the kidney and the adrenal glands. Sensors in specialized kidney cells monitor the amount of sodium, potassium, and water in the bloodstream.
Fill a plastic bag with ice and wrap it in a towel. Apply to the neck, between the shoulders, or at the base of the head for 20 minutes. Apply a hot application, such as a hot shower or bath, a heating pad, hot water bottle, or hot towel, for 20 minutes. Repeat this for thrice a day until you get complete relief from the stiff neck. Note: you can use artificial cold pack or bag of frozen peas.
So here are six stretches you can do to help loosen your neck and shoulder muscles, without the need for equipement. The exercises are taken from Prevent Back Pain: Upper Back and Neck Exercises For A Correct Posture. View the video here. Neck and Shoulders.