Listeria can survive and grow in refrigerated food. It can be killed by heating foods to “steaming hot,” or 165 degrees Fahrenheit, the CDC says. But that’s not always possible — or palatable — for foods that are made to be eaten cold.

A listeria outbreak linked to ready-to-eat sandwiches and snacks has sickened at least 10 people in the U.S., and a producer is voluntarily recalling dozens of products sold to retail stores, hospitals,