When staying in the Atacama desert, in the North of Chile, we visited a “Salt lake” called Cejar Pond. Even more salty than the Dead Sea, it’s 10x more salty than the ocean (c. 40% saturation), giving incredible buoyancy.
But this was May, so autumn, and the top of the lake actually had ice on it! Undeterred, we climbed in – unbelievably, 2m down the water had been warmed by the desert sun, it was just freezing at the top.
There was a problem if you lost control and floated on your tummy – as you got stuck in the freezing cold water at the surface!