International audienceWe investigate an application of the method of fundamental solutions (MFS) to heat conduction in two-dimensional bodies, where the thermal diffusivity is piecewise constant. We extend a recent MFS for one-dimensional heat conduction with the sources placed outside the space domain of interest (Engng. Anal. Boundary Elements 32, 697-703, 2008), to the two-dimensional setting. Theoretical properties of the method, as well as numerical investigations, are included, showing that accurate results can be obtained efficiently with small computational cost