I think it's try-this-at-home science experiment day. Today, we'll look at an experiment that shows off the principle of convection, in which heat transfers through the mass motion of something fluid, which of course means water but can also mean air. It's how hurricanes get to forming, among a lot of other things.
It's very simple; all you need is some warm water dyed one color and cold water (or ice cubes) dyed another color. I've seen some videos also use a tub filled with lukewarm water to initially separate the two, but the video I'm going with doesn't do that. So you really can't get much safer to try at home than this; the only real risk is spilling the tub and you can just go outside to do it if you're scared of that.