I have always known that there are certain oils that can be used in cooking (heated) and some that are best used in a cold state for full benefit.
The Spectrum company has a great online resource that can be useful in the kitchen. It's a kitchen guide that shows which oils can take heat and how much. It also shows you which oils should not be heated and the best Omega 3-6-9 sources. I printed one out so I can use it as a reference. I will put it into my 3 ring binder along with my recipes.