The Herning Boys Choir does its best to keep it together.

Danish musician and self-proclaimed “chili enthusiast” Claus Pilgaard, aka Chili Klaus, is a YouTube star known for his Chilismagning series, where he invites celebrities to eat chili peppers with him. For one of his most diabolical challenges, Klaus asked the Herning Boys Choir—a choir he once sang for—to see if it could make it through a performance of “O Come All Ye Faithful” after consuming ghost peppers.

The ghost pepper is the 7th hottest chili pepper in the world and clocks in at around 1 million SHU or Scoville Heat Units. For some perspective, the average jalapeno pepper is measured at about 5,000 SHU.

The video starts with the boys sounding great until 1:27 when they pop in the peppers. At 1:54, you can see them sweat as the heat ratchets up. The ghost pepper got its name because the heat sneaks up on you. At first, it tastes sweet and then the heat begins to envelop your entire head.

The fact that these kids kept singing is impressive. None of them give up until the song ends, then they all rushed to the nearest water fountain.

Chili Klaus & Boys Choir On Fire 🔥

"Some of these kids just kept going like it was nothing. Respect,” one commenter wrote on the video with over 2 million views. “I love how some of them would stop and look at one another for reassurance and that they are in it together,” another wrote.

“The fact that they all stuck through until the end was amazing. Definitely a great team-building exercise,” a commenter wrote.