The precautions an organization should take place:
- Entire infrastructure or architecture should be as close as production
- Various kinds of testing to be preformed
- Accounts to be used against these enviornments
- Revenue impacts
- Automated testing if any, which test scenarios to be executed
Since these environment is very close to real production environment, tons of weired behavior of application or product can be detected early on in release cycle in help avoiding last minutes or production emergencies.
However, one should not perform entire testing on these environments. Say a day or 2 days execution of various tests is good enough!