Which of the following should be monitored when using cold therapy?

When using cold therapy, monitoring skin color is crucial because it provides direct insight into the tissue's response to the cold. Cold therapy, while often effective for reducing inflammation and numbing pain, can lead to adverse effects such as reduced blood flow. If skin color changes to pale, blue, or develops a mottled appearance, it may indicate that the tissue is not receiving enough blood or oxygen, potentially leading to frostbite or tissue damage. Observing changes in skin color helps ensure that therapy is being administered safely and allows the caregiver to respond promptly if any complications arise. This vigilance helps maintain the health of the tissue being treated.

The other factors—breathing rate, blood pressure, and heart rate—are generally not the primary concerns with cold therapy application. While overall monitoring of a patient’s vital signs is important in a broader clinical context, in the specific case of cold therapy, skin color is the most relevant indicator of the therapy's physiological impact on the local area being treated.