In this paper, a macro-scale, phenomenological constitutive model for shape memory alloys is used in conjunction with energy balance equations to study the temperature profile and hence deformation profile seen in SMA wires under specific boundary conditions. The general, fully coupled thermo-mechanical problem is formulated, but analytical solutions are determined only for the decoupled case. Results for two specific boundary value problems are presented here: (1) resistive heating of an SMA wire - initial detwinned martensite leads to strain recovery (contraction) on heating; (2) deformation migration in semi-infinite SMA wire cooled at the boundary - deformation zone propagates and expands as initially austenitic wire transforms to martensite (expansion). In both cases, the region and extent of transformation is identified, indicating the magnitude of actuation obtained. Implications of the modeling for active control of structures are discussed.