Final answer:
The temperature of heat used to curl resistant hair varies between 180-220 degrees Celsius (356-428 degrees Fahrenheit), depending on the hair's thickness and texture. Using high heat on resistant hair may cause damage, so precautions should be taken.
Step-by-step explanation:
The temperature of heat used to curl resistant hair depends on the method of curling. One method is using thermal means, where heat is applied to the hair to form curls. The temperature used can range between 180-220 degrees Celsius (356-428 degrees Fahrenheit), depending on the thickness and texture of the hair. It is important to note that using high heat on resistant hair can cause damage, so it is recommended to use heat protectant products and avoid excessive heat exposure.