Space suits have all sorts of tubes and wires inside
Outer space is not a very welcoming environment for humans. The extreme temperatures, lack of oxygen, and micrometeoroids flying around are only some of the dangers people must be prepared to face. In order to survive, astronauts must be well equipped and well dressed.
That is why their space suits look so blocky. This picture shows what they look like on the inside. All those wires and tubes are meant to keep them safe from extreme conditions they might face outside the protection of Earth’s atmosphere.