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.
1 Fresh roasted, quality whole bean coffee. Don't grind yet!  Coffee is best brewed at temperatures between 92 and 97C, or about 192F and 204F. Guess what - a kettle, just off the boil, once poured, is at the top end of this temperature. Air cools the first bit real quick.