Spent 8 hours kayaking in 9/10 uv index sun on first exposure very white legs. From just above the knee and covering the feet is reddish purple. Got back home and took A 4 hour nap. Woke up with chills and goosebumps. Yellow rings around swollen knees. Trying to stand up, feels like legs are being crushed in A vice. Unbearably painful from bone to skin. Feels like muscles are tearing from bone also. Legs and feet quickly swell to nearly double their size. Laying back down and elevating them, within 30 minutes, 70 percent of swelling subsides. Try to stand for restroom, 10/10 pain in legs from knees to toes, pressure feels like they will pop. Day2 swelling less rapid, pain when legs are lower than body level darts stabbing the interior of legs. When legs dangle, pressure feeling starting, feeling full to stretching skin on feet and ankles to maximum. Fully verticle, quickly threatens the unbearably intense pain. While applying pressure to stand, pain becomes 10/10 immediately and must sit again. Day3 small clusters of blisters forming all over legs. The outter burn though severe is hardly A bother, as compared to the internal pains. Leg swelling while resting down by 85 percent in the right leg and 70 percent in the left leg. Experiencing ability to fight through the pain after A few minutes to walk to bathroom, left leg much more painful. Cannot feel much in left leg as responses to direction for movement. Mostly dragging left leg. After 2 to 3 minutes the pain returns, especially in the left leg. Within 5 minutes swelling of legs fills the lose pants and shoes to painful levels. By the time I can get back down and remove garments the feet and legs look look balloons. Day4 Was blisters not developing as in youthful sunburns. Stood twice today for 3 to 4 minutes. Left leg still horrible and quickly swelled or caused me to lay back down. Right leg seemingly 1/4th of the way better. Watching blisters for signs of infection, nothing bursting yet. Clusters of seed and rice size blisters. Must shift body dozens of times while sleeping prevent throbbing internal pain in legs or swelling. I am looking forward to sleeping now and waking to day 5. I hope to report any improvements. I am documenting this experience, as I have never had such an internal reaction from A sunburn before. I have been entirely sunburned as A young boy with 2nd degree symptoms and full body blisters. I have also suffered severe cramping from dehydration while cross country summer backpacking in my youth. No reaction from the sun has ever caused my legs to double in size from standing up. If there is anyone who can shed some light on the kind of damage I may have caused, I would greatly appreciate it. I don't have the best lower extremity circulation, and the pants while in the sun were rolled tightly above the knee. It is possible that not enough blood circulated to cool the cooking areas of my legs? I do remember by buttox going numb multiple times from sitting for so long in yr kayak. Is my goose cooked? Any specialist info on this subject would be greatly appreciated.