Bracelet That Warns if You Are Taking too Much Sun

A group of researchers at the University of Strathclyde in Glasgow, Scotland created a bracelet that warns the user if it is exposing to the sun too.
Alert bracelet goes from yellow (as seen in photo) to blue with a pink stripe. This happens by the ultraviolet rays that generate a chemical reaction in the components of the device, as a result of this reaction releases an acid on a layer of dye that produces the color change.
One of the unique qualities of this device is that it can be adjusted to an instantaneous signal, i.e. that changes color when the sun just starts to hurt.
The idea of this invention is not only used as a bracelet, but also in clothing and bikinis for people to take precautions when ultraviolet rays are starting to attack, and this is no small thing that places like the UK die 2300 people annually because of skin cancer.