There are surely going to be times when experiments must continue running on their own while you do other things (go to lunch, or go home to sleep). At these times, it's important to consider all the things that could go wrong in your absence and to prepare for them.
For example, what would happen if there were a power failure and the stirrer were shut down? What if the water gets turned off or a cooling hose detaches? Get the idea? Cooling hoses need to be clamped or wired on. What about the water shut down? Do you need a special sensor for water, temperature, pressure, fluid level, etc. to control the experiment in your absence?
The name, address, and phone number of the person responsible for an experiment should be prominently displayed. In addition, clear directions should be provided on how to safely shut down the experiment in your absence. Special hazards and precautions should be noted. Your experiment shouldn't become someone else's land mine.
Don't allow experiments to run unattended unless they are failsafe.