A gentleman called me the other day and asked me about surge protectors. A typical surge protector power strip is built using Metal Oxide Varistors (MOV's). A cheapest kind may use just one varistor, from hot (live, active) to neutral. A better protector would contain at least three varistors; one across each of the three pairs of conductors (hot-neutral, hot-ground, neutral-ground).
While a MOV is designed to conduct significant power for very short durations (~8/20 microseconds), such as caused by lightning strikes, it typically does not have the capacity to conduct sustained energy. Under normal utility voltage conditions, this is not a problem. However, certain types of faults on the utility power grid can result in sustained over-voltage conditions. Examples include a loss of a neutral conductor or shorted lines on the high voltage system. Application of sustained over-voltage to a MOV can cause high dissipation, potentially resulting in the MOV device catching fire. The National Fire Protection Association (NFPA) has documented many cases of catastrophic fires that have been caused by MOV devices in surge suppressors, and has issued bulletins on the issue.
I have found a company that makes surge protectors that does not use MOV's. They are Brick Wall, a division of Price Wheeler Corporation. I have purchased several of their products over the years and have never had a failure.