How hot is the deep abyss?

The temperature in the deep abyss of the ocean, particularly at the bottom of the Mariana Trench, can range from just above freezing to around 4°C (39°F). However, the heat from hydrothermal vents can elevate temperatures significantly, sometimes exceeding 400°C (752°F) in the surrounding water due to the extreme pressure. Overall, the deep abyss is generally cold, but localized areas can be extremely hot due to geothermal activity.