It sounds like what you want to do is pretty simple, but from the foregoing explanations, I'm not able to understand the requirement. Can you give a bit more detail about what you're switching and why? I'm guessing its a power supply and equipment that heats up and can stay on until the temp is 50 degrees. If 100 degrees is reached (how? because it was turned off at 50) a fan comes on and everything else must be off?