By 1 million years ago (mya) Homo erectus had moved out of Africa into the cooler climate of Asia and Europe. They were enabled to do so by their ability to devise technology to cope with the new environments.
This included the use of caves, as at Zhoukoudian, and of huts constructed in the open air, as at Terra Amata.
In addition, H. erectus had gained mastery of fire. Claims have been made for the early use of fire, including a possible hearth at Chesowanja around 1.5 mya, and it is certain that H. erectus were using fire by 0.5 mya at Zhoukoudian.
Fire was not only important as a source of heat. It also warded off predators, and could be used to panic animals, driving them where they could easily be trapped and killed. In addition, using fire to cook food rendered it easier to tear and chew and made it more easily digestible.
