It is a procedure in which a small scope (like a flexible telescope) is inserted into the bladder and ureter and it is used to diagnose and treat a variety of problems in the urinary tract. For ureteral stones, it allows the urologist to actually look into the ureter, find the stone and remove it.
The answer, though, is within reach: cold-brew coffee, a style that has enjoyed a recent resurgence for its natural sweetness, its lack of acidity and its simplicity. While a hot cup of coffee will have a stronger aroma and flavour, heat also brings out the bitter flavours of a bean.
This material is a solid at room temperature but will melt into a liquid when heated by the coffee. This melting sucks out just enough heat to cool the coffee to 140 degrees and transfers small bits of that energy back into the liquid over a long period of time to maintain the 140 degree mark.