Were my black girls at??👀💕

I need some advice. I never did a hot oil treatment before.Is it safe to leave the oil in your hair.Because I'm YouTube I saw some girls not heat it just put it straight in their hair but the directions say to heat in water,massage on scalp, cover it with a warm towel for 3-5 minutes, then rinse it out with warm water.I don't want to go bald.O need some help and is this really successful?

(Advice from anyone is good I just specified black girls because they more likely have the same hair type as me)