Apparatus and methods are provided for treating a human condition by providing an appendage chamber having a thermal exchange member. Negative pressure may be applied to a human appendage when placed within the appendage chamber. Blood flowing through the arteriovenous anastomosis (AVA) of the appendage may be heated or cooled at the thermal exchange member for therapeutic application of thermal energy to adjust blood viscosity in the human to alleviate symptoms associated with a number of autoimmune, circulatory, neurological, lymphatic, and endocrinal maladies. A load sensor may be coupled to the thermal exchange member and configured to measure a force of the appendage applied to the thermal exchange member. In addition, a negative pressure sensor may measure pressure within the appendage chamber.
