While lounging beneath a patio umbrella with a fan at a Los Angeles outdoor party in August, the author of “The UV-Tracking Gem made me rethink how sunlight affects my health, not just my appearance,” felt exhausted, dizzy, and nauseous, classic signs of heat exhaustion. Yet, armed with a UV-tracking necklace called Gem from The90, costing a cool $249 (or $149 at the time), they were convinced they were shielded from both sun and heat. The Gem app, however, disagreed, flashing a notification that their UV exposure had soared significantly—prompting the author to ponder whether their health, not just their appearance, was truly protected from the sun’s rays.

The first major claim is that sitting under a patio umbrella and near a powerful fan guarantees protection from both heat and UV radiation. While an umbrella does block direct sunlight, it often fails to shield from reflected UV rays—especially on a sunny day in Los Angeles where the sun’s rays can bounce off water, sand, or even the patio furniture itself. Moreover, fans circulate air but don’t reduce the ambient temperature or UV intensity; they merely create a personal breeze. So, while the author felt cool, their skin might have been baking under UV rays that the umbrella couldn’t block—especially since the Gem app indicated a high UV exposure.

Assuming the $249 (or $149) price tag makes the Gem a worthwhile investment, it’s worth questioning whether the app’s accuracy matches its cost. UV tracking devices vary in precision, and many rely on general estimates of UV index rather than real-time measurements at the wearer’s exact location and angle. The author’s experience might simply reflect a misalignment between the UV index reported by the Gem and the actual UV conditions—perhaps the UV index was higher than the Gem accounted for, or the necklace was positioned incorrectly relative to the sun. For the price, one might expect a more nuanced analysis of UV exposure, including variations across different parts of the body or throughout the day.

Lastly, the article suggests that the Gem’s UV tracking fundamentally reshaped the author’s understanding of sunlight’s impact on health. While UV radiation certainly affects skin health, causing everything from sunburn to long-term skin aging and cancer risks, it’s also a key regulator of vitamin D synthesis, mood, and circadian rhythms. The Gem might have highlighted that the author’s UV exposure was higher than anticipated, but without integrating temperature and humidity data, it’s unclear whether the device distinguished between peak sun hours or accounted for cloud cover. Thus, while the Gem provided a useful snapshot of UV exposure, it might have led the author to overemphasize UV’s role in their health woes, overlooking other factors like dehydration, heat stroke, or even the psychological impact of being stuck under an umbrella for too long.