The purpose of this study is to determine if local warming of surgical wounds improves healing and helps prevent infection. The investigators want to see if warming surgical incisions improves oxygen levels and healing in skin close to the incision.

Surgical site infections (SSI) account for 37% of US hospital infections and increase morbidity and cost. High rates (10-22%) of SSI are associated with colorectal surgery and obesity. Bacterial resistance requires oxygen and higher tissue oxygen limits infection in general surgery patients. Control of core and local temperature may increase infection resistance by modulating perfusion, oxygenation, angiogenesis and immune cell responses. Perioperative hypothermia reduces tissue oxygen while normothermia lowers SSI rates. Warming injured tissues locally may offer additional benefit. Warming incisions immediately after surgery and intermittently for two days after gastric bypass or colectomy surgery reduced infection rates in a pilot sample. Systematic study of clinical outcomes and potential mechanisms in a larger study is lacking and is the focus of the current study.

Inclusion Criteria:

• 18 and older,
• scheduled for bariatric, colon or gynecological surgery,
• able to speak and read English.

Exclusion Criteria:

• glucocorticoids greater than 5 mg per day,
• albumin below 3.0,
• creatinine above 2.5 mg/dl,
• history of pulmonary edema.