It's my redneck side.. Well part of my redneck side anyway...
To turn the heat on you have to turn a valve under the hood that allows coolant into the heater core. You close the valve for summer use or you'll get really hot.
When I was young my Dad had a Scout just like this one. He took my mom and me in it on a trip across Wyoming to South Dakota in the heat of the summer pulling a small travel trailer. I sat in the back of the Scout. My mom wouldn't let us roll the windows down because she didn't want to get her hair messed up.. Gosh it was a hot box in there. Old Scouts are all metal with no insulation. So every morning I'd get up early and ride as far as I could get on my bike. That was the best part of my day. Then they'd catch me up and I'd have to ride in the hot box the rest of the day.
They did let me ride my bike through the center of Yellowstone Park though and that was the highlight of my trip. That and riding along the Gallitan River. I don't know what cycling is like in Yellowstone Park these days. There's probably too much traffic for it now.
If you want to take the slow boat to South Dakota, drive there in an International Scout pulling a travel trailer across Wyoming in the heat of the summer with the windows rolled up... Did I tell you how well you could hear the motor running?.. I liked it so much that when I grew up I bought my own Scout!