Physio Hub: Evidence-Based Article

The Never-Ending Question: Ice Pack or Hot Pack?

Ice Pack

< Key Points >

  • Cold therapy reduces inflammation and pain, ideal for acute injuries and recovery, but effectiveness varies and requires healthcare consultation.
  • Heat therapy enhances blood flow and tissue elasticity, easing chronic stiffness and pain, especially useful during athletic warm-ups.
  • Both therapies require careful application to avoid skin damage, with effectiveness and safety best determined with professional guidance.

Muscle strains, pulls, and soreness are common issues most people feel occasionally. If you are looking for some at-home treatment options, you may have heard to apply ice or heat. But which one?

It can become challenging to figure out which to use and when. Plus, there still needs to be more conclusive research on which works better. However, becoming educated on heat and cold therapy may help you decide what would work for you. The article below looks at what is involved with heat and cold therapy when they may help, and precautions to take.

What is Cold Therapy and How Does it Work?

Cold therapy involves the application of cold for therapeutic purposes, also called cryotherapy. It may include: 

  • Ice bath 
  • Appling ice packs
  • Ice massage 

According to research in the journal Extreme Physiology & Medicine, cold therapy works by reducing tissue temperature and cell swelling. This leads to alterations in blood flow, specifically vasoconstriction. The constriction of the blood vessels reduces blood flow to the area, resulting in a slowed rate of inflammation and decreased tissue damage. Cold therapy may also numb tissue, slowing down the pain signals from the brain. 

According to a research article in the Scandinavian Journal of Medicine & Science in Sports, cold therapy is often used in sports medicine to treat acute soft tissue injuries and reduce recovery time. It may provide some benefits in the following conditions: 

  • Runner’s knee
  • Tendonitis
  • Sprains 
  • Arthritis pain 
  • Low back pain 
  • Pain after a knee replacement 
  • Treatment after reconstructive surgery

However, studies do not provide a definitive recommendation for the use of cold therapy. Without an exact consensus, it is best to speak with your healthcare provider to determine if cold therapy is a good option for your specific injury. 

Ice Pack
Hot Pack

What is Heat Therapy and How Does it Work?

Heat therapy involves applying heat to injured or damaged tissues, joints, and muscles in the body. Heat therapy may include: 

      • Moist heat
      • Hot packs
      • Heating pads

Heat may reduce pain associated with muscle stiffness. A research article in Postgraduate Medicine found that heat therapy may increase blood flow to the area and improve the elasticity of the tissues. This may result in reduced pain and stiffness. 

Heat therapy may be useful in the following:

      • Chronic muscle stiffness
      • Arthritis
      • Tendonitis
      • Sprain and strains

Research in the journal Sports Medicine found that heat therapy was especially useful during a warm-up. The heat helped maintain increased core and muscle temperature during the transition phase. Athletes may also benefit from heat therapy to reduce soreness and cramps and increase flexibility. 

Although some research supports the use of heat, it is not conclusive. For instance, a study in the Archives of Physical Medicine and Rehabilitation involved patients with low back pain who used continuous low-level heat wraps and those who did not. The group that used the heat wrap reported less pain than those who did not. However, research indicated that the effectiveness of heat therapy may depend on the depth of the tissue affected. 

Discussion

Although it is common to implement hot and cold therapy for injuries, evidence remains limited on which modality is best and when. For instance, an article in the World Journal of Clinical Cases indicates that anything that reduces inflammation, such as cold therapy, may actually delay healing. This is because the inflammation process plays a role in recovery itself.

While heat may provide short-term pain relief, the evidence for its overall effectiveness is also lacking.

Understanding the benefits, risks, and limitations of both hot and cold therapy is important. It is always best to get an opinion from a healthcare professional if needed.

While both cold and hot therapy are generally safe, some precautions should be taken. Injuries to the skin are possible.

According to Johns Hopkins Medicine, it is important to apply ice cautiously. Putting ice directly on the skin can cause tissue damage. Wrapping ice in a thin towel is advisable to protect your skin from injury from the ice. Apply the ice for short periods of about 10 to 20 minutes several times each day.

Similarly, it is important to exercise caution when applying heat therapy. Excess heat can damage the skin and further exacerbate an injury.

In addition, consider some of the general guidelines for using hot and cold therapy safely.

  • Neither heat nor cold therapy should be used on an open wound.
  • Avoid cold therapy if you have poor circulation unless directed by your doctor.
  • Do not use heat therapy on an area with an infection unless instructed by your physician.
  • Use either type of therapy with caution if you have nerve or sensory damage and have difficulty sensing temperatures on your skin.

< Reference >

  • White GE, Wells GD. Cold-water immersion and other forms of cryotherapy: physiological changes potentially affecting recovery from high-intensity exercise. Extrem Physiol Med. 2013;2(1):26. doi:1186/2046-7648-2-26
  • Stocks JM, Taylor NAS, Tipton MJ, Greenleaf JE. Human physiological responses to cold exposure. Aviat Space Environ Med. 2004;75(5):444-457.
  • Swenson C, Swärd L, Karlsson J. Cryotherapy in sports medicine. Scandinavian Med Sci Sports. 1996;6(4):193-200. doi:1111/j.1600-0838.1996.tb00090.x
  • Fuentes-León P, Jara-Poblete N, Bastías-Sánchez P, Vitzel KF, Marzuca-Nassr GN. Heat transfer by three types of hot pack and its implication on the flexibility of the lower back: a randomized, controlled trial. Fisioter Pesqui. 2016;23(2):201-209. doi:1590/1809-2950/15088923022016
  • McGowan CJ, Pyne DB, Thompson KG, Rattray B. Warm-Up Strategies for Sport and Exercise: Mechanisms and Applications. Sports Med. 2015;45(11):1523-1546. doi:1007/s40279-015-0376-x
  • Bongers CCWG, Hopman MTE, Eijsvogels TMH. Cooling interventions for athletes: An overview of effectiveness, physiological mechanisms, and practical considerations. Temperature. 2017;4(1):60-78. doi:1080/23328940.2016.1277003
  • Gabbett TJ. The training—injury prevention paradox: should athletes be training smarter and harder? Br J Sports Med. 2016;50(5):273-280. doi:1136/bjsports-2015-095788
  • Mac Auley DC. Ice therapy: how good is the evidence? Int J Sports Med. 2001;22(5):379-384. doi:1055/s-2001-15656
  • Wang ZR, Ni GX. Is it time to put traditional cold therapy in rehabilitation of soft-tissue injuries out to pasture? World J Clin Cases. 2021 Jun 16;9(17):4116-4122. doi: 10.12998/wjcc.v9.i17.4116. PMID: 34141774; PMCID: PMC8173427.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8173427/
  • Malanga GA, Yan N, Stark J. Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury. Postgrad Med. 2015 Jan;127(1):57-65. doi: 10.1080/00325481.2015.992719. Epub 2014 Dec 15. PMID: 25526231.https://pubmed.ncbi.nlm.nih.gov/25526231/
  • Mayer JM, Mooney V, Matheson LN, Erasala GN, Verna JL, Udermann BE, Leggett S. Continuous low-level heat wrap therapy for the prevention and early phase treatment of delayed-onset muscle soreness of the low back: a randomized controlled trial. Arch Phys Med Rehabil. 2006 Oct;87(10):1310-7. doi: 10.1016/j.apmr.2006.07.259. PMID: 17023239.https://pubmed.ncbi.nlm.nih.gov/17023239/