What you are asking to do is possible but it is tricky. What you need to do is create a setup that will allow you to keep track of the state it is in. I have done this for several components that do not have discrete on/off or discrete modes.

Read this to get an idea
[Link: remotecentral.com]

you can also do a search for "+state" in the ng section.

I think it will be a little trickier as you will be switching between several temps. Certainly NOT easy but I think possible.