If you do ignore all the expert advice and fire someone impetuously, perhaps because you had an argument or you caught the worker in the act of stealing or damaging property, what should you do?
The answer depends on the worker's previous history with your company. You can start by going through the worker's file to see if you have enough documentation (of previous violations of rules or of poor performance reviews) to justify your action. If you do, you can heave a sigh of relief because you'll have a defense ready in case the worker decides to sue you.
If you have little or no documentation of any previous problems with the worker, the safest course of action would be to call him or her, say that you acted too quickly, and offer to reinstate the worker. If he or she refuses, you have just transformed the firing into a voluntary quit, so your possible liability has decreased dramatically. If the worker agrees to come back, you'll naturally keep a watchful eye on him or her. Hopefully things will improve; if not, be sure to document any problems before you repeat your hasty conduct.
If you don't want to take the worker back, perhaps because his or her conduct was so appalling that it would justify firing in itself, or because you feel your ability to work together has been destroyed, you should first gather and save any available evidence that supports your version of what happened.
Then, after reviewing the evidence, you have a choice. You can sit tight and
hope the whole thing blows over, or you can try to work out a deal with your
ex-employee: you can agree to provide some severance benefits to the worker, in
exchange for a signed release form that waives his or her right to sue you.