What brought it on, I now know was chronic dehydration. I spent the weekend outside working hard in the relative coolness. It was only 75-80 degrees where it had been a constant 85-90 for a week or more. So I was not thinking too much about my water intake until Sunday afternoon hit, and I realized I was overheating.
Of course at the point of overheating, one is far too dehydrated to simply drink more water and be done with it. I began rehydrating dutifully, and became aware of the UTI symptoms late Sunday afternoon.
Symptoms included constant urging to urinate, passing scant and cloudy urine, burning pain after.
My first attempt at a remedy (besides rehydrating) was homeopathic Apis mellifica 30C, which is indicated in burning, hot pain. After the first dose, the symptoms were gone for 12 hours, returning Monday morning. I hesitantly took a second dose Monday afternoon, and symptoms were gone only for a couple of hours.
This indicated that Apis was not the correct remedy so I switch to Cantharis 30C. I took one dose Monday evening, and all symptoms have happily been absent since.
Cantharis is the preeminent remedy for urinary tract problems such as incontinence. It was probably helpful here because of the incessant urge to urinate, and general discomfort in the urinary tract and bladder, where Apis has no special affinity to these organs.