A patient warming device with patient access for maintaining normothermia and/or treating hypothermia is provided. The device includes a first compliant layer and a second compliant layer sealed together around an outer border to contain a liquid between the two layers and to form a wrap that surrounds and conforms to a body portion of a patient. A plurality of flaps extends from opposite sides of a generally longitudinal central portion of the wrap, such that one or more flaps from the opposite sides fasten to each other to surround the body portion. The flaps are openable during functional use to provide access to an underlying patient body surface. A continuous fluid flow path extends between the first compliant layer and the second compliant layer between a fluid inlet and a fluid outlet to carry liquid and deliver heat through the wrap.