The UV-tracking Gem made me rethink how sunlight affects my health, not just my appearance

With temperatures rising to the 90s in Los Angeles, avoiding the heat wasn't exactly an option while I was at a relative's outdoor party in August. So I sat beneath a patio umbrella with a powerful fan nearby, figuring I was protected from the sun and heat. Half an hour later, I felt exhausted, dizzy, nauseous, and generally unwell, symptoms consistent with heat exhaustion.

Around the same time, I received a notification from an app used by the $249 ($149 at the time of publication) UV-tracking necklace I'd been wearing, called Gem, from a company called The90. It warned that my UV exposure had climbed considerably. It turns out UV radiatio …

Read the full story at The Verge.