This is interesting its a plaster that alerts you when you have been in the sun too long. The plaster has been created by scientists in Scotland and is sensitive to ultraviolet light. It works by changing colour when the wearer is at risk of sun burn. The plaster costs 10p and will be available either as a wristband or a sticky plaster. It will also be able to detect ultraviolet rays when it is worn under a swimming costume. It is thought that the device will radically cut the chances of developing skin cancer caused by prolonged overexposure to the sun because it can take between four and eight hours for sunburn to show on the skin by which time damage has been done. The plaster should help warn people before this happens. People do need to be aware that they need to cover up when in the sun and put on a sunscreen that provides adequate protection, the plaster might alert you that you have been in the sun too long but it is better to be aware of the risk first.