I am surprised no one else has complained about this one.
Both the HV and non-HV Camry's if NAV equipped come with a little suppliment booklet describing the operation of the NAV and Voice Command system.
If you happen to look at the list of Voice Commands the list is identical to the Prius and includes Climate Control commands like "Auto On/Off", xx Degrees, etc. etc.
Well, guess what?
They are fake.
There is no Voice Command interface to the Climate Control system on the Camry.
The Prius does but not the Camry.
Don't feel too bad though.
The '07 Lexus RX350 has a similar/identical NAV and their documentation lists the same Voice Climate Control Commands and they too are non-functional.

A call to "Toyota in the Sky" and the Lexus equivalent resulted in both saying it is a documentation error and the feature is not supported.

Just an FYI.
I'd LOVE for someone to prove this observation as wrong.
I really miss not being able to demo the voice system by saying "Seventy Degrees" and having the system respond "Setting the temperature to seventy degrees".
J