A Brazilian ad agency has come up with a creative way to teach kids about the dangers of sun exposure. It’s made dolls with skin that “burns” in sunlight unless protected.

The campaign, to promote Nivea, involves male and female dolls coated in a material that is sensitive to ultraviolet light. Unless the skin is either covered or coated in sunscreen, it gradually turns redder and redder. The painful looking shade is strongest in the areas of skin most likely to burn on a child.

The agency passed out the dolls free of charge to families on a beach in Rio De Janeiro, along with bottles of sunscreen. The idea is that kids play with the dolls and learn the importance of applying sunscreen, making them more likely to either remember to apply it to themselves, or at least not scream and shout when their parents try to interrupt their play to top them up.

There are a couple of limitations to the effectiveness of the dolls. One is that they have a fixed smile that remains in place even when they are apparently in burning agony. The other is that the setup means that applying sunscreen after the event appears to immediately undo the effects of the burning, which isn’t exactly how things work in the real world.