  The spatial string tension for 3+1 dimensional QCD at finite temperature is
measured. The gauge configurations we re generated with two light and one
heavier strange quark on lattices of size $16^3 4$ and $24^3 6$. This spatial
string tension is compared with the string tension of the 3 dimensional pure
gauge theory together with the temperature dependent 2-loop running coupling.
Further comparison is made with predictions from dimensionally reduced
effective theories.
