I use the crock pot more than anyone I know, so I don't notice the heat from cooking that way.
Otherwise, if I want something quick, Cottage cheese and crackers, peanut butter and crackers. I always have bread here, and lunch meat individually wrapped in wax paper in the freezer. Two slices of lunch meat right from the freezer are just right after 75 seconds in the microwave. I always have corn tortillas on hand and slices of cheese can be rolled up in tortillas and heated a few seconds in the microwave.