This was done by a professional and only for demonstration purposes, to show how viscous the molten rock is ***
***Please consult with professional guides who are safety conscious if you are thinking about such a trip. Much of this new land is highly unstable and large chunks can fall into the ocean without warning, or you can be on top of an emptying lava tube and that can collapse. With the intense heat, sharp rocks and constantly changing lava flows, you can easily get trapped or hurt and thus should be careful and go with professional guides. ***
When the lava emerges from one of the vents at Kilauea, it comes out at 700 to 1,200 °C (1,292 to 2,192 °F), and begins to make its way to the path of least resistance.
This video shows how pressure applied to this dense material only causes a slight indentation. While this may not be surprising (it is liquid rock), I think that many people think of lava as more of a hot-watery-like substance. You would never fall into a lava lake the way you would a swimming pool, the molten rock is much more dense, so you would simply land on it, sink a little, and be burned.