How do you heat a curler up?

Depends on what type of curler you got.

If you got an oldschool one with no cord and is just a round peice of metal, there is a special tool that is made of iron and you heat it up with an electrical outlet while letting the actual curler set inside.

if you got a standard curling iron with a plug, plug it in.

if youre talking about individual curlers, plug it in or

DONT HEAT THEM! some are made of plastic and will melt.