I once attended a presentation by a professor that ran the burns unit at a Red Cross Children's Hospital. My OH was raising funds from an open day at one of their fire stations and I was fortunate to be a guest at the presentation. One aspect of his speech stuck with me. He said that for the same amount of exposure (hot water, oil, sunlight) that an adult may have then the burn would be more severe for a child...because children's skin is thinner.
It's so important to cover up in summer. The skin cancer rates in Australia are horrendous.