Probably a good idea to use musician's ear plugs (something like the Etymotics Ety Plugs) after the technical run through at that point.
Do the run through without, to double check and confirm everything is GTG, then use the plugs to attenuate by 13-20db, while still allowing for decent fidelity (unlike regular foam plugs which tend to attenuate higher frequencies making things sound muffled).
I've used (and still use) Ety plugs for certain applications, and they work well.
I bought these to try
for both, the slightly different design, that fits about flush to the ear canal (with small, flexible tabs for easy extraction) AND the convenient metal keychain case included. I now keep these on my keychain 24/7, in case I inadvertently find myself in a loud environment without advanced planning.