I would have to go with hair curling tools too.
They would need to be heated to a fair temperature for them to work efficiently though their appearance may give the impression that they would scorch the hair but in the hands of a skilled coiffeur, that wouldn't be the case and I'm sure they would have ways of determining if they were too hot before use.
I suppose they are no different in many respects to using an old flat iron....they were exposed to quite high temperatures in order for them to work but unless they were left in contact with the material being ironed for too long, they didn't scorch things.
When I was serving my time as a church organ builder in the early 60s we still used flat irons for certain jobs.
When electric irons were first introduced, they were the cause of many a scorched shirt or bed sheet or even a fire.
Also today's curling irons/tongues certainly get very hot, hot enough in fact to give nasty burns if the come into contact with exposed skin but rarely damage hair if contact time is limited and hair is slightly moist or protected with appropriate hair protection fluid.
