Inside a pharmaceutical plant, heat is everywhere—and until recently, almost nobody was paying attention to it.Steam rising from boilers. High-temperature reactions turn raw inputs into finished drugs. Buildings and manufacturing lines are kept at precise temperatures around the clock. For decades, the fuel behind it all was natural gas, cheap enough that nobody questioned it and complex enough that nobody wanted to touch it. Then came Covid. Then, Russia's invasion of Ukraine. Then the Iran conflict, which sent gas prices surging 60% to 100% and fertilizer costs up 40%, shocks that rippled through supply chains from pharmaceuticals to food to...