How to Correctly use Ice
Since the majority of the bleeding occurs within the first few minutes of injury, ice should be applied immediately afterwards. Around the first 15 to 30 minutes of cold application, local vasoconstriction decreases blood flow and subsequently reduces swelling. Applying ice for a longer period of time will initiate the hunting response. This is the body’s complete switch from vasoconstriction to vasodilation in the region as blood vessels increase in diameter and allow more blood flow. This happens after approximately 15 to 30 minutes of icing the extremities depending on the individual, and continues to cycle between vasoconstriction and vasodilation. It is the body’s protective mechanism to prevent cell death in the limbs and extremities from ischemia (low oxygen) related to decreased blood flow. This means that after long exposure to cold temperatures, the body will reintroduce blood flow in order to feed the tissue with more oxygen. This protective vasodilation lasts approximately four to six minutes, and promotes swelling which is typically counterproductive.
This is not the case of more is better or personal preference. With regard to the above information, we recommend that you ice an injury no more than 15 to 30 minutes at a time. Afterwards, remove the ice and allow the tissue to gradually rewarm at room temperature and regain its normal homeostasis (biological balance). Giving the limb a break is important. Icing for too long delays the healing process since it reduces local metabolic rate, including metabolites involved in healing. After two hours, you may use ice again and repeat the same steps. The first three minutes of icing should feel cold, followed by 15 to 30 minutes of analgesia (pain relief) where the pain threshold is increased. The time frames can be quicker or longer in some individuals depending on body type and/or the size of cold application. The longer you apply the ice for the further the cold will penetrate your body which is helpful for deeper injuries. Therefore, it is a good idea to adjust duration of application according to what works best for you and your situation. You may also notice that your skin is a pinkish-red color right after removal, and this is mistakenly presumed to be vasodilation. It is actually an increase of oxygenized hemoglobin (oxygen-carrying molecules of your red blood cells) at the site of application.
Continue to page 4 to know when to use ice and when to avoid it