The American Red Cross advises using a digital quick response thermometer to check the temperature of frozen foods. If food is above 40 degrees, consider it thawed, and the clock is ticking on how soon it should be used.
Here is a chart from the American Red Cross, advising what foods to keep, and what to discard. http://www.redcross.org/services/disaster/0,1082,0_564_,00.html#foodchart
More advice here: http://www.redcross.org/services/disaster/0,1082,0_564_,00.html