Inside the Rise of Bitcoin-Powered Pools and Bathhouses

The scene inside Bathhouse, a spa in Manhattan, is one of complete serenity. Visitors recline in 105-degree pools, surrounded by cedar tiles and elegant marble slabs from Brazil. But just beyond closed doors, in harshly-lit back rooms, an unexpected source helps forge the bliss: rows and rows of continuously-running Bitcoin mining computers.

The idea of a Bitcoin mine heating a pool sounds strange. The machines run constantly to find new Bitcoin and safeguard the Bitcoin network. The...