Polymer insulators and methods of using polymer insulators are disclosed. In some embodiments, a method includes separating a first portion of a subject's tissue from a second portion of the subject's tissue so that there is a space between the first and second portions of tissue. Deionized water, a buffered saline solution, liquid polymers, gels, particles, foams, and/or gases are disposed between the first and second portions of tissue, and the first portion of tissue is exposed to energy to treat the first portion of tissue.