This week in Key West health
A weather station at the airport, a federal tide gauge in the harbor, and a UV model are doing this page's homework right now. The strip above is live: the heat index from National Weather Service station KEYW, today's UV curve, the barometer's three-hour trend from NOAA station 8724580, and any active alert for the island. Read it the way locals read the sky. If the heat index is past 100, move the tennis match to sunrise. If UV is 8 or better, the burn happens faster than the beer gets warm. And if the pressure is falling, stretch first; your knees already knew.
What the heat index means here
The National Weather Service heat index scale draws its lines at numbers this island crosses routinely: caution starts at 80, extreme caution at 90, and danger at 103, where heat exhaustion becomes likely and heat stroke stops being theoretical. Key West runs humid, and humidity is the whole trick. Sweat only cools you when it evaporates, and on a July afternoon here it mostly cannot, so a 91 degree day can bill your body for well over 100. The thermometer is the sticker price; the heat index is what you actually pay. For the people training in it, the runners and the paddlers, Key West Sports Medicine's Heat Safety Advisor runs the same numbers against a workout instead of a beach day.
What UV numbers mean on an island
The EPA UV index runs from 1 to 11 plus: 8 through 10 is very high, and 11 or more is extreme, which is where a cloudless Keys midday sits for much of the summer. Water is the multiplier visitors forget. The surface reflects UV back up at you, so a day on the flats or at the sandbar taxes your skin from two directions at once. Shade, real fabric, and reapplied sunscreen are the whole defense; the index just tells you how honest you need to be about it.
The barometer and your joints
Falling pressure ahead of a storm is the most consistent flare trigger my joint patients report, and I believe them. The research is honestly mixed: Smedslund and Hagen went looking in "Does rain really cause pain?", their 2011 systematic review in the European Journal of Pain, and found no reliable link once the data were pooled, even though a minority of patients really did seem to track the weather. The waiting room and the literature disagree here, and I let them. On falling-glass days, warm up longer and let the first game be a rehearsal. The warm-up that answers a falling-glass morning is written out in PickleInjury's warm-up guide, and it transfers to any sport that starts cold.
This month on the island
Bathtub-warm water and a storm most afternoons. Reef cuts infect faster now than in any other month.
Wondering something the strip cannot answer? Ask Doctor Key West and it may become a column.