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 is the same reason you want to drink your drip brewed coffee as soon as it's finished brewing - leaving it on the heating element for too long can also burn the coffee. For a French press, you want your water to be somewhere around 195 degrees.