The UV index is climbing.

And just in time comes the UVSunSense, a plastic wristband touted to monitor sun exposure and tell you when to reach for the sunscreen, and when to get out of the sun.

Place the band on the wrist, colour side up. Apply sunscreen to skin and the wristband, which then turns purple when exposed to UV and UVA rays. Reapply sunscreen when the band fades. Cover up or head inside when the words “Apply sunscreen to this side” completely disappear.

UVSunSense president John Horovitz says the recyclable bracelet is calibrated to work with a minimum SPF 15, and will respond with higher levels of protection. It especially helps parents keep an eye on their kids’ sun exposure, he says. (See www.uvsunsense.com for more info.)

But Dr. Cheryl Rosen, of the Canadian Dermatology Association, notes: “There are differences between different people in how sensitive they are to UV ... You should be out there when you need to be out there, to be active, playing a game of tennis, canoeing, but you don’t want to stay out there until the second before you burn.”

As well, says Rosen, “I don’t know if the amount of sun you get on your wrist is the same amount that you get on your nose,”

The bands are available to Canadians online (www.amazon.com or www.drugsdepot.com) for $5.87 (U.S.) for a seven-pack.

Environment Canada scientists predict that UV radiation levels will be three per cent higher this summer than pre-1980 levels, due to the thinning ozone layer.