Oh good DQ has explained it nicely. Sorry it's not a passing thing, well probably not until you are on a plan and back out of ketosis. It's useful in the summer, but in the winter have warm soups and shakes, and other allowed drinks, heating up, extra clothes, if all else fails remember it is a good thing and will make you thinner. Above all keep your BigPants on!
It did always make me feel leaner too!
Dizzy x