More than a third do not think they could identify symptoms of skin cancer, such as new moles, itchy or bleeding moles or moles that change colour or shape, according to a recent research study by the Nuffield group.
Despite warnings that sunburn can lead to skin cancer, a third say they are burned once a year or more.
Nearly a quarter of parents with children of school age say their child is sunburnt at least once a year and 26% of younger parents aged between 16 and 34 say their child burns at least three times a year.
The health charity said its UK hospitals have seen a 16% rise in skin cancer cases among 16 to 34-year-olds since 2007.
