it's 1200°C so you burn already before your body even hits the lava. During the Pompeji eruption people got killed by the hot ash (arriving first and travels further) which cooked them alive:

> The individuals in the boat houses died relatively quickly: The volcanic ash blocked the entrance to each structure, and the temperature of the air within probably rose to about 400°C—even hotter than a wood-fired oven. -- https://www.sciencemag.org/news/2020/01/studies-reveal-grues...