As I understand it, refined oils are treated chemically or are pressed in a way that produces high heat in order to extract the maximum amount of oil. The controversy over canola oil arose over the use of hexane in the refining process.
http://www.spectrumingredients.com/product/gen_info/oil_extract.html
In Europe, “cold-pressed” or expeller-pressed oils do not rise above 90 degrees F during extraction and retain the most nutritional benefits and flavor. In the US, the upper limit is 120 degrees F–by custom, not regulation, I think. So, that’s why extra virgin olive oil is used in salad dressings and as a finishing touch to dishes. Virgin olive oil has a higher smoke point than extra virgin olive oil but is still inrefined and may be available in bigger cities. “Light” olive oil has been refined (higher extraction rate, neutral flavor) and is marketed for “cooking” though Bertolli’s website says that their light OO is cold-pressed, making it a better choice, IMO, than any refined oil–even if it’s not guaranteed to be a lower temperature pressing.
I like the oils from The California Olive Ranch–very good quality, all cold-pressed. We were visiting wine country and watched the pressing of the harvest and enjoyed a tasting there.