Transmission locks up on 1996 Volvo 850

I can drive my 850 wagon, no problem starting up. Drive
it a while, stop, inside temperature sensor registers high. Have to use shift override to get in gear and then it moves a bit and stalls.

Asked by for the 1996 Volvo 850
Are all of these things occurring at the same time? Only at the same time, not independent of each other?
all occurs at the same time
This is going to require a physical inspection to know what is going on. It may be the ignition switch, but the symptoms are not quite consistent with that. Do you have a place that can look at this for you? A Volvo shop?