Idiots on the internet image - Humor, satire, parody

Seems like they are playing with magnesium. Or possibly another alkali or alkaline earth metal. When mixed with water, it give, interesting results.

lol, the alkali metals are as follows: Lithium, Sodium, Potassium, Rubidium, caesium, and Francium. Magnesium is not an alkali metal...

I know that, I said:
Or alkaline earth metal.
"Or possibly another alkali or alkaline earth metal."
I had them reversed, I should have said:
Or possibly another alkaline Earth or alkali metal.

ok but only the elements i listed will react with oxygen in the way shown in the .gif magnesium doesn't react with oxygen in this way :P it only rusts...

Under normal room temperature you are correct, but notice, they heat it with what it seem to be a lighter.

well, that's not only about the effect, I wouldn't want to be in that bath after reaction...

Regarding of medical issues, it would depend which element was used and what would be the product.
Magnesium oxide is for heartburn relief so I wouldn't worry about it. Magnesium peroxide is used as a laxative, so I would worry about that one either(well as long you don't take a substantial quantity =P). But if they used calcium for example, calcium oxide create skin irritation in addition to damage to the lungs. But hey, if they were stupid enough to trow reactive material when they were in the bath, I wouldn't expect extensive health precaution from them.