  We demonstrate a simple technique for adding controlled dissipation to
Rydberg atom experiments. In our experiments we excite cold rubidium atoms in a
magneto-optical trap to $70$-S Rydberg states whilst simultaneously inducing
forced dissipation by resonantly coupling the Rydberg state to a hyperfine
level of the short-lived $6$-P state. The resulting effective dissipation can
be varied in strength and switched on and off during a single experimental
cycle.
