What's the point of wrapping hair with a warm towel with any hair treatment?

I read several times when people use any hair treatment (oil or cream), they usually say wrap the hair in a towel...is this necessary?? what does it do exactly coz I usually put the oil or cream and leave them on without wrapping my hair in a towel..what's the point??


And should it be warm?? How can I get it warm??What's the point of wrapping hair with a warm towel with any hair treatment?
The idea is that the heat helps the product to penetrate your hair/skin depending on whether it is a hair/scalp/skin treatment. You warm a towel by pouring very hot water over it and then wringing it out or if you have access to one: use a professional steamer!