McDonald’s burger sold in a two-compartment heat-retaining package from 1985 was the McDLT.
The McDLT was designed around temperature contrast. Its special packaging kept the hot patty and lower bun separate from the cool lettuce, tomato, cheese, and upper bun until the customer assembled the sandwich.
The product was introduced in the United States in 1985 and became known for the packaging as much as for the burger itself. Advertising emphasized keeping the hot side hot and the cool side cool, a concept that made the item distinctive among fast-food sandwiches.
The McDLT was eventually discontinued, and its packaging created more material waste than a conventional burger container. It is sometimes confused with the McLean Deluxe, another short-lived McDonald’s burger, but the two products had different recipes and marketing concepts.