Final answer:
Archaeans are adapted to extreme environments such as high heat and are known as extremophiles, including thermophiles and hyperthermophiles.
Step-by-step explanation:
The organisms that are typified by being adapted to extreme environments such as high heat are archaeans. These microorganisms are known as extremophiles, particularly the ones that thrive in high temperatures, called thermophiles or hyperthermophiles.
Bacteria and archaea consist of prokaryotic cells and some of them have adapted to extreme conditions, such as environments with high heat, which can indeed be found in places like hot springs or hydrothermal vents.