It is a pronoun.
no it doesn't cold drinks cool you down the most and the hot drink that definitely does not cool you down is a hot chocolate
I
It will cool down.
It can be, as in "I need to cool down" or "The hot oven will eventually cool." Cool is often an adjective.
they slow down.
Place the hot glass in a slight draught will help it to cool slowly and avoid cracking.
Put ice in it
sweat
Because after performing a show/act the performer will be warm/hot and will need to cool down.
plural noun
One can cool down hot baby items such as pureed food by placing a small ice cube inside the bowl or dish and stirring. One can cool down a hot baby bottle by placing it in a cool water bath or stream for a few minutes before serving.
same as water, numbnuts