That message has been slow to catch on, despite a spate of illnesses last year from improperly microwaved frozen foods. On Sunday, the government issued a new warning urging consumers to thoroughly cook frozen chicken dinners after 32 people in 12 states were sickened with salmonella poisoning.
"Given how people use microwaves, it's great for reheating, but maybe not so good for cooking," said Doug Powell, scientific director of the International Food Safety Network based at Kansas State University.
The problem is that microwaves heat unevenly, and can leave cold spots in the food that harbor dangerous bacteria, such as E. coli, salmonella or listeria. So microwaving anything that includes raw meat, whether it's frozen or thawed, can cause problems.