A thermal dissipation system for wearable electronic devices transfers heat away from a housing enclosing a heat source and dissipates the heat through a region of the support assembly that is noncontiguous with the housing. The support assembly may be coupled to the housing to enable the housing to be worn by a user. Various regions of the support assembly have different thermal resistances between a thermal conduit and an ambient environment. The thermal resistances may decrease as the thermal conduit becomes farther away from the heat source. The variations in thermal resistances enable modulation of relative heat flux between the various regions. For example, heat may be internally routed through the wearable electronic device to be dissipated through a surface that a user does not typically touch during operation.