Instead of exploding with a poison cloud, it has a much more violent flaming explosion. If Samus approaches them, they will react aggressively by charging towards her and detonating on contact. Its tubes can be frozen over by the Ice Beam, but this prevents the creature from expelling the volatile gas within, which in turn causes it to explode after a while.
"Flying low in the air, Bulls will explode if they get too close to Samus. The Heat Bulls in Sector 3 will charge at Samus, so try to fight at a distance."
- The Magmoor Caverns Puffers in Metroid Prime and Gel Puffers in Metroid Prime 3: Corruption (both creatures that heavily resemble the Bulls in physiology), share behavioral similarities with the Heat Bull, such as being able to live within super-heated areas and detonating in a fire-based explosion, respectively.