Unless there's something actually, or expected to soon be, in play? Not really. A big part of that is simply experience and a good amount of planning ahead.
Aquarium break? I've got a couple spare aquariums that can be set up in next to no time--along with totes, tubs, air pumps, hoses and such. And I keep a rotating stock of 3g or so of treated water on hand.
Filter malfunction? I've a spare HOB I can set up and stuff with the finer media and a net bag for the bigger stuff that I can clip to the side of it to keep the bacteria alive and working til I can order a new one (as well as a small savings account specifically FOR such emergencies).
New fish? Quarantine tank, drip-line, spare buckets and the knowledge that I've done my research before introducing a new fish. Worse case? Well, we're back to those spare aquariums and supplies.
Illness? Been there, done that. Spare tanks to move out stock who can't handle the treatment or to set up as seperate QT and the knowledge to handle most of the common issues. Uncommon issues? I head here and pick the brains of TPT.
Folks may quibble about costs and space issues--but having materials on hand for backup just makes sense.