Sia wasn't messing around for her new video for "Fire Meets Gasoline" -- bringing in the big guns ... aka, Heidi Klum and her underwear.
Sure, Pedro Pascal from "Game of Thrones" is there, too. But, we repeat -- Heidi Klum. Underwear. Literal fire.
Check out Heidi's 10 sexiest moments ... just don't get burned!
Now feel the heat with the entire music video!