Certain electrical fields, when applied across a cell membrane, can have the sole effect of membrane permeabilization, which is referred to as electroporation. When the permeabilization is irreversible, the effect leads to cell death, primarily due to loss of cell homeostasis, in a process known as irreversible electroporation (IRE). This is an unusual mode of cell death that is not yet fully understood. However, it is unique among tissue ablation techniques in affecting only the cell membrane while tissue molecules, everything encompassing collagen structures to proteins, remain intact. This facilitates a possible immune response and avoids scar tissue formation. Irreversible electroporation is, therefore, substantially different from any other tissue ablation technique and has many advantages over either heating or freezing thermal ablation. However, since IRE employs electrical fields, it can produce thermal effects which could cause thermal damage if parameters are not chosen correctly, therapy negating the advantages of IRE. This study evaluates the temperature distribution during typical IRE protocols as a means to establish the electrical parameters that produce IRE alone, without thermal effects. (C) 2008 Elsevier Ltd. All rights reserved.