They are dangerous to all those around him, including humans. Both geldings and intact males will develop these teeth. They need to be removed at the gum line, which can be done by your veterinarian quite quickly using OB wire. The teeth may in time grow back, and the procedure needs to be repeated, so they should be checked for regrowth periodically. Occasionally, females will develop a significant set of fighting teeth that also should be cut, although this is not as common.
Heat stress claims the lives of many llamas every year.
Proper grooming, including shearing, is required especially of long-wooled llamas. Shade and ventilation, including the use of fans to circulate air around the llamas can prevent the occurance of heat stress in all but extreme conditions. They should have access to shade, air flow, and fresh, cool water. Some breeders add electrolytes to the water source. Pools of water such as kids' plastic wading pools are sometimes used by the llamas, as are natural ponds and streams.