As the temperatures begin to climb it is important to maintain healthy food storage habits.
The USDA Food Safety and Inspection Service website provides useful information and tips for reducing bacterial growth and thus spoilage of food. Freezing and refrigerating food is a method of food preservation based on reducing the rate of bacterial growth in the food. At lower temperatures, bacteria tend to grow at a slower rate. This is because growth is regulated by enzymes, and the work of enzymes is temperature (and pH) dependent.
In BioMI 2911 at Cornell University, we investigated the growth rate of E. coli at different temperatures. It was found that the growth rate (per minute) was 0.0005 at 22C, 0.011 at 30C, 0.048 at 37C, 0.012 at 45C and ~0 at 55C. The most rapid growth occurred near body temperature, and the slowest growth occured at temperatures below (22C) and far above (55C) room/body temperature. This is consistent with some of our practices of food preservation: freezing and cooking.
So, in the warm weather ahead don't forget to refrigerate leftovers!