The goal of this randomized control trial is to test a patient directed self-monitoring and self-management intervention aimed at preventing the recurrence of chronic venous leg and diabetic foot ulcers using skin temperature and cryotherapy (cooling). We propose MUSTCOOL, a novel ulcer prevention strategy for patients at highest risk for developing chronic ulcers; those with a previous history. We aim to compare a cooling treatment to a placebo to determine the outcomes on ulcer recurrence, pain, physical activity and quality of life. Individuals with newly healed chronic ulcers will be invited to participate in MUSTCOOL's two component intervention: 1) self monitoring skin temperature over targeted hot spots daily with an infrared thermometer; and 2) maintenance cooling with a cooling pack (or placebo pack) placed over the hot spot three times each week for 30 minutes. If the temperature of the hot spot becomes elevated 2F above baseline (average of 30 days of daily temperature readings) for 2 days in a row, a bolus regimen of 5 consecutive daily, 30 minute applications of the cooling or placebo pack will be implemented. We will monitor safety and side effects, however, there have been no reported adverse events reported in our previous cryotherapy studies. We designed this chronic ulcer prevention intervention that targets the remodeling phase, the final repair process of healing after chronic ulcer closure. The skin environment is particularly vulnerable to ulcer recurrence due to a persistent aberrant inflammatory state. Our previous research has demonstrated that cooling this skin reduces the abnormal metabolic activity, protecting it against ulcer recurrence. Recent advancements in infrared technology allow us to take images of the affect skin to identify the area that has the highest temperature or vulnerable hot spot. These hot spots will be self monitored by patients with newly healed ulcers in the home with an infrared thermometer that date and time stamps each reading. The study's outcomes on physical activity will be evaluated with an accelerometer. We hypothesize that by improving the skin environment and reducing pain, patients will more likely be physically active and have better quality of life, all measurable goal for this study. We will evaluate this prevention strategy over six months in 180 patients, 90 of whom will be randomized to receive the cooling pack and 90 the placebo. Our goal is to test this non-pharmacological, non-invasive clinical intervention as a tailored self-management strategy to prevent chronic ulcer recurrence. It will also determine alleviation of symptoms such as pain, and the debilitating effects on physical activity and quality of life.