Ice and Heat for Neck Pain

Overview
For decades, the advice has been to use ice packs for acute injuries, trauma or pain, and typically heat after about three days.
Heat increases circulation, increases flexibility and increases metabolism, while ice reduces circulation, edema (swelling), inflammation, and spasm.
RESCU Treatment Ratings
R = Risk E = Effectiveness S = Self-Care
C = Cost U = Usefulness (overall rating)
1 = Least Favorable 5 = Most Favorable
RISK: 5/5
Generally, and especially in comparison with other treatments for pain, hot and cold packs are considered pretty safe.
Injuries can occur from burns if heat, such as through hot packs, is too hot or left on for too long. Patients with reduced sensation, such as numbness or diabetic neuropathy, should use heat and cold with care. Ice burns can also occur if the skin is cooled too much. Some conditions can be worsened with heat or cold.
Products for Treatment
Ice and Heat for Neck Pain Treatment Instructions
For decades, the advice has been to use ice packs for acute injuries, trauma or pain, and typically heat after about three days. It makes sense: ice may reduce inflammation and swelling, slow the conduction of pain impulses and hopefully reduce pain. Heat is thought to increase blood flow and relax muscles.
The research suggests ice may help reduce pain, but studies are somewhat contradictory. However, use of ice is generally safe and quite inexpensive. Similarly, continuous heat wraps may be more effective than ibuprofen or acetaminophen according to a couple studies. Again, the research is not particularly definitive.
For ice packs, you can use frozen corn or peas, commercial cold packs, or a small resealable bag, such as a ZiplockÒ, filled with crushed ice. Apply ice for 10-20 minutes (not longer) once an hour while you are up. Don’t fall asleep with an ice pack, and always use a thin towel between the ice pack and your skin to avoid an ice burn.
Similarly, heat packs are widely available. You can also wet a small towel, such as a dishtowel and microwave it for 20-45 seconds. Be careful not to burn yourself. Moist heat is thought to penetrate more deeply, but any source of heat, such as an electric heating pad may help. Heat should generally not be used for more than 15 to 20 minutes per hour since the tissue needs time to return to a normal temperature periodically or it can become damaged.
Sources:
Nadler SF, Steiner DJ, Erasala GN, Hengehold DA, Hinkle RT, Beth Goodale M, Abeln SB, Weingand KW, Continuous low-level heat wrap therapy provides more efficacy than Ibuprofen and acetaminophen for acute low back pain, Spine 2002 May 15;27(10):1012-7