how do you change the air/heat in the backseat from the front controls on 2007 GMC Yukon XL Denali

I to often have to turn around and reach back to the back seat and have to change the temperature when my kids turn it to 80 degrees! and find myself wondering why it's so hot and realize it's cranked all the way up in the back. it many times becomes hazardouse when I have to reach in the back while I'm driving. it's a big problem please help.

Asked by for the 2007 GMC Yukon XL Denali
Owners manual!! Just turn off rear controls from the front selector.