144-Pack Heat Sensitive Color Changing Pencils - Fun Hot Dots Markers for Kids Art Projects, Classroom Activities & Creative Writing

They do change color if you rub them, but just holding them didn't seem to do it most of the time. I called the company and the lady I talked to said maybe they were cold from the air conditioning in the truck so we let them warm awhile and they did get a little better...but I probably won't order them again.