Electric oven won't heat up. ?

It is a Jenn Air. I don't know what model. However, when I turn it on it will only heat up to 100 F. The heating elements are not turning orange. So that makes me want to say it's them but it's hard to believe they would go out at the same time. I'd like and try to fix it myself, so if anyone could leave me detailed (dumbed down) instructions that would be great.