Chefs don't do it! The amount of people I see heating olive oil......please don't do it! Olive oil spoils under heat and even light. It should be kept in a dark cupboard in a dark container if possible. When you heat olive oil you change its composition from one of a healthy fat to a bad fat- yup BAD!
Buy extra virgin which is the best pressing of the oil and use it raw on salads or to dress up a plate but never ever cook or heat it.
If you need to heat an oil use coconut oil, which is heavenly and can be heated to a high temperature without spoiling - its health benefits are immense- or make clarified butter. Ghee is also another cooking product, which is essentially clarified butter but put in posh tubs and sold for a fortune in health food shops.