This study is a randomized controlled trial of mild hypothermia during liver transplantation to provide protection from AKI. Participants will be randomized to normothermia (36.5-37.5 °C) versus mild hypothermia (34-35 °C) during a portion of the liver transplant operation. The protocol is based on preliminary data from rodent models showing that hypothermia protects the kidneys from ischemia-reperfusion injury, as well as studies in deceased organ donors showing that cooling improves post-transplant organ function. Temperature will be maintained with standard techniques plus a minimally-invasive esophageal cooling device that is approved by the U.S. Food and Drug Administration. The investigators hypothesize that mild hypothermia will reduce the incidence and severity of AKI after liver transplantation(LTx). Standard surrogates (e.g., change in serum creatinine, need for initiation of dialysis) and biomarkers will be used to assess the severity of kidney injury.