In mi­cro-chan­nel gas flows, ve­loc­ity slip and tem­per­a­ture jump must be ap­plied at the fluid/​solid in­ter­face to take the ther­mo­dy­namic non-equi­lib­rium into ac­count in the vicin­ity of the wall. In this work, sim­u­la­tions at mol­e­c­u­lar scale have been car­ried out and shown a jump in the con­duc­tion heat flux, in agree­ment with the bound­ary con­di­tion pro­posed by Maslen (1958) in con­tin­uum me­chan­ics.