What makes THIS cave one of the deadliest places on Earth?

Deep beneath a Mexican mine lies the Cave of Crystals, a breathtaking cavern filled with colossal selenite formations. Discovered in 2000, its extreme heat and humidity make it incredibly dangerous, limiting visits to mere minutes even with protective gear. This geological wonder, with crystals reaching up to 37 feet, remains largely inaccessible to the public due to the life-threatening conditions.