  We study causal viscous hydrodynamics in the context of central relativistic
heavy-ion collisions and provide details of a straightforward numerical
algorithm to solve the hydrodynamic equations. It is shown that correlation
functions of fluctuations provide stringent test cases for any such numerical
algorithm. Passing these tests, we study the effects of viscosity on the
temperature profile in central heavy-ion collisions. Also, we find that it is
possible to counter-act the effects of viscosity to some extent by re-adjusting
the initial conditions. However, viscous corrections are strongest for
high-mass particles, signaling the breakdown of hydrodynamic descriptions for
large eta/s.
