Systems for treating a subject's tissue can include a thermally conductive cup, a tissue-receiving cavity, and a vacuum port. The vacuum port is in fluid communication with the tissue-receiving cavity to provide a vacuum for drawing the submental tissue, or other targeted tissue, into the tissue-receiving cavity. A thermal device can cool and/or heat the conductive cup such that the conductive cup non-invasively controls the temperature of subcutaneous lipid-rich cells in the tissue. A restraint apparatus can hold a the conductive cup in thermal contact with the target region.