The McDLT (McDonald's Lettuce & Tomato) was a burger with hot beef and cool toppings, known for its "Keep the hot side hot, and the cool side cool" slogan, served in a unique two-part styrofoam container that kept the meat separate from the lettuce, tomato, cheese, and pickles, but it was discontinued in the early 1990s due to environmental concerns over the foam packaging, leading McDonald's to switch to paper-based materials.

What it was: A burger featuring a hot beef patty on one side and cold lettuce, tomato, cheese, and pickles on the other. Advertised with the iconic jingle and the promise of perfectly temperature-controlled ingredients.

Why it was discontinued:

Environmental Impact: The polystyrene (Styrofoam) container was a major environmental issue, leading to its removal from the menu.

Packaging Changes: McDonald's transitioned away from foam packaging for sustainability reasons.