Human: Is a curling iron necessary in curling? Assistant: 
No, a curling iron is not necessary in curling. A curling iron is a tool used to make the hair curly using heat and the sport of curling requires curling brooms, stones (rocks), and curling shoes, so changing the structure of your hair has no practical benefit to the sport of curling. Changing the structure of your hair has no practical benefit to the sport.