Heat transfer rates across various types of soft solder joints are investigated between 0.06 and 0.5°K using a3He−4He dilution refrigerator. For Cd‐Bi junctions and thin (10 &mgr;) Sn‐Pb junctions, the heat flux per unit area and unit temperature difference is 4.7×106T2.74erg/sec. This rate is about twice that predicted by the theory of Little. Junctions of Sn‐Pb and Sn‐In about 40 &mgr; thick have a much lower conductance. The thermal conductivity of bulk Sn‐Pb solder is found to be 9900T2.31erg/sec‐cm‐°K.