The worst mistake you could possibly make with an extension cord is to create the so-called suicide cord. This is when you plug an extension cord or power strip into another, a "chain" from the outlet to get more plug space or range. If that wasn't bad enough, there might be an additional risk: old surge protectors. Unbeknownst to many, you should throw away your old surge protectors because they become a fire hazard. Play it safe and find other outlets rather than creating daisy chains, and chuck out those surge protectors so old you can't remember when you bought them.