It's difficult to tell sometimes when you've had too much sun, but a new product called SunSpots may help change that. Manufacturers of the 1-inch, bandage-like sticker claim they can reveal how much sun exposure a wearer has received.
Each SunSpots sticker contains radiochromatic materials that change color upon exposure to the sun's ultraviolet rays. The sticker is placed on the skin and covered with the sunscreen the user normally wears.
As the period of time and intensity of exposure increases during the day, the design on the sticker disappears until the SunSpots sticker becomes a solid red. After that, the wearer should either use higher SPF sunscreen, get out of the sun for the day, cover up, or apply a sun block to exposed skin.
The product is being developed by Indico Technologies Inc. SunSpots are not yet on the market, but soon they will be available at drugstores.