Being inside a giant microwave would be an extremely dangerous and harmful experience. Microwaves use electromagnetic radiation in the form of microwaves to heat food by exciting water molecules within it. When you stand in front of a standard household microwave oven, the door is designed to prevent the microwaves from escaping, keeping you safe.
However, if you were somehow inside a giant microwave where the radiation was not contained, it would be an excruciating and life-threatening situation. The microwaves would penetrate your body and start to rapidly heat the water molecules inside you, causing intense burns, tissue damage, and potentially even lethal injuries. The experience would be agonizing and could lead to severe burns, organ failure, and death.
It's important to remember that microwaves are designed to be safe when used properly, but being inside one or exposed to uncontained microwave radiation would have catastrophic consequences. This scenario is entirely hypothetical, and it is crucial to avoid any attempts to recreate it in real life.