I was going to do this post as a magic Monday until I read about all the people who have been burned doing this trick, so perhaps it is better left as one that you binge YouTube videos of.
The trick is that you take boiling water outside in frigidly cold temperatures and toss the water into the air. As the water hits the air it condenses into a cloud of snow.
The boiling water is why this works, but it is also why it can be dmgerous. As you add heat energy to water the molecules get further apart from each other, this is what turns the water into steam. But more importantly for this experiment is that the near boiling water has a larger surface area than cooler water would. This means that the very cold air, in my case -25°C (-13°F), hits much smaller droplets of the near boiling water than it would of cooler water.
The next part that makes this work is that air this cold doesn’t hold much moisture. This means that the water condenses and precipitates out almost as soon as it hits the air. Hence, the very hot water turning into a cloud of snow as it hits the very cold air.
So, why is this dangerous? It’s the boiling water. Although a lot of the water does turn to snow, there are some drops that are too big to condense that quickly. These drops can get caught by the wind or simply just fall where you didn’t expect and catch you or a bystander, causing severe burns often on the face.