👉 The term "hypogean" refers to a region on Earth's surface where the temperature is lower than that of the oceanic surface. This area extends from the equator towards the poles, and it is characterized by high temperatures below 10°C (50°F), with some regions reaching as low as -27°C (-46°F). The presence of this region on Earth's surface has significant implications for climate change, particularly in relation to the polar ice caps.