The solutions for flow and heat transfer in a steady laminar boundary layer flow are presented analytically for an electrically conducting viscoelastic fluid, subject to a transverse uniform magnetic field, past a semi-infinite stretching sheet. The temperature profiles and thermal characteristics at the wall are drawn and tabulated for selected parameters with prescribed surface temperature (PST) and prescribed surface heat flux (PHF) conditions. We also give the asymptotic solutions for temperature when the Prandtl number is very large. It is found that the inclusion of Joule heating has a significant influence on the thermal characteristics at the wall and the wall heat transfer strongly depends on the Prandtl number Pr as well as the Eckert number Ec. The heat flow may transfer from the fluid to the wall when Ec is large rather than from wall to the fluid when Ec is small. A physical argument about the thermal characteristics at the wall is proposed.