Olive, sesame, peanut, and sunflower are among the oils obtained from cold pressing. Cold-pressed oils retain all of their flavour and aroma, and contain natural antioxidants that help prevent oil oxidation, thus keeping them from going rancid. Cold pressed oils containing mostly unsaturated fatty acids, will degrade when heated. The higher the content of unsaturated fatty acids (poly-unsaturated) in the oil, the less suitable it will be for cooking at high temperatures. Some cold-pressed oils, such as olive oil, are stable at high temperatures because they contain a high amount of mono-unsaturated fatty acids. Some oils, like sesame oil, are so unsaturated they should not be used for stir fries, sautés nor before grilling. Grilling temperatures are very high, sometimes higher than frying temperatures. The heat not only damages the fatty acids, it can also change them into harmful substances. Oils that are higher in saturated fats or mono-unsaturated fatty acids are the most stable when heated.