According to the ServSafe Manager curriculum and the FDA Food Code, foods that require Time/Temperature Control for Safety (TCS food) must be stored at an internal temperature of $41^{\circ}F$ ($5^{\circ}C$) or lower to inhibit the growth of pathogenic bacteria. A ham-and-cheese sandwich is a prime example of a TCS food because it contains protein-rich ingredients (meat and dairy) that are moist and neutral or slightly acidic—the ideal environment for bacterial multiplication.

Ham is a processed meat that, while cured, still requires refrigeration to remain safe. Cheese is a dairy product that is also classified as a TCS food. When combined in a sandwich, the product becomes a "ready-to-eat" TCS food. If left in the Temperature Danger Zone—defined as the range between $41^{\circ}F$ and $135^{\circ}F$ ($5^{\circ}C$ and $57^{\circ}C$)—bacteria such asStaphylococcus aureusorListeria monocytogenescan grow to dangerous levels. In contrast, beef jerky is a shelf-stable dried meat with low water activity ($a_w$), cookies and brownies are low-moisture baked goods, and uncut fruit (except for certain melons, tomatoes, and leafy greens once cut) is generally not considered a TCS food. Proper storage at $41^{\circ}F$ or lower ensures that the sandwich remains safe for the duration of its shelf life, which is typically a maximum of seven days if prepared on-site. Managers must ensure that refrigerated storage units are calibrated and that the internal temperature of the food, not just the ambient air of the cooler, remains at or below the $41^{\circ}F$ threshold.