Kitchen
What the Two-Hour Rule Is Really For
Perishable food should not spend long stretches sitting at room temperature because bacteria can multiply rapidly as food warms. FDA advises refrigerating or freezing perishables, prepared food, and leftovers within two hours, or within one hour when the temperature is above 90°F.
The rule is useful because it gives you a clear decision point for leftovers, takeout, picnics, and party food. It is easier to follow a clock than to guess whether something still seems safe.