Studies of heat conduction and microwave absorption in the vortex state of
kappa-(BEDT-TTF)(2)Cu(NCS)(2) reveal some of the specific aspects of superc
onductivity in this system. Moreover they allow us to probe the destruction
of bulk superconductivity by a magnetic field. The two set of results yiel
d identical magnitudes for the upper critical field with a temperature depe
ndence distinctly different from the one suggested by the onset of resistiv
e transition.