A heat sink includes a heat sink base/riser, a first fin, and a second fin. The spacing between the base/riser and the first fin and the second fin, restively, may be adjusted by rotating a threaded rod. The threaded rod includes a first threaded knurl that is engaged with the first fin and a second threaded knurl that is engaged with the second fin. The thread pitch of the first threaded knurl and the second threaded knurl may differ. For example, the pitch of the first threaded knurl may be smaller than the pitch of the second threaded knurl if the first fin is located nearest the heat sink base/riser relative to the second fin. The spacing of the heat sink fins may be adjusted based upon the current operating conditions of the electronic device to maintain an optimal temperature of a heat generating device during device operation.