How to make sure you're not on the production website in Drupal 7?
Environment Indicator is designed to do that:


  This module will help you to keep sane while working on your different environments by adding a configurable color bar to each one of your environments. The Environment Indicator adds a coloured bar on the site informing you which environment you're currently in (Development, Staging, Production, etc.). This is incredibly useful if you have multiple environments for each of your sites, and like me, are prone to forgetting which version of the site you are currently looking at.