The compound which gives chilies their heat is called capsaicinoids, and higher concentrations make the plant more pungent. The heat is ranked on the “Scoville scale” which measures each pepper in Scoville heat units (SHU). Bell peppers are rated as 0 SHU while the world’s hottest pepper, the Carolina Reaper, is rated at 2,200,000 SHU. The Jalapeño ranges from 2,500 to 8,000 SHU.