According to leaf.tv, Temperature can certainly affect your hair's health and appearance, whether it is living in a dry, cold climate or extended use of a hot curling iron. However, there is no clear-cut evidence that temperature can actually alter your hair's growth rate, which tends to be about a half-inch per month for everyone.
In general, too much heat can lead to brittle, damaged hair and split ends. The most common source of excessive heat exposure is extended use of heat-based styling tools such as curling irons or hair dryers. While these devices can be safe and healthy when used properly, over time they can have a negative effect. On the other hand, heat can also encourage blood flow to follicles in the scalp, and it can cause cuticle scales to open, making conditioning treatments more effective. While heat can damage or help your hair, depending on the situation, it generally does not affect the rate at which your hair grows.
Cold can also have an effect on hair. In a clinical context, cold can sometimes diminish the effects (good or bad) of chemotherapy or medical hair treatments by reducing blood flow to the scalp follicles. As an environmental factor, cold air can make hair more brittle, dry and fragile, as well as increasing static. While some people claim that hair growth increases in winter to provide additional insulation, medical studies have not shown this to be true.
CASTOR OIL - protects your hair from heat: If you apply castor oil to your strands, it’ll essentially act as a protectant—which is particularly good if you’re doing heat styling. “Apply the oil on semi-dry ends,” recommends Dr. Burg. “It protects against high heat appliances and helps to prevent frizzy results.”