Air Conditioner is always on

I cannot stop my air conditioner in Toyota Solara 2002 from cooling. When I press the AC button - no reaction, keeps cooling. Is this an electrical problem? Can I turn AC off manually, it is freezing outside, but AC keeps cooling.

Are you using the defogger? Alot of newer cars automatically turn on the AC with the defogger. If it blows cold in another setting, I would suspect that the button may have stuck, or perhaps the pulley is stuck in the on position.