I've had lots of problems with old volvos (122, 144, 164) and hot
starting. I live in a desert where the temperatures regularly get
above 120(f) on roads and in parking lots. The engines clearly get
lots hotter than that. The problems have always been easy to solve.

On one, it was the carbs being wildly out of sync. I synced the
idle and mixture and butterflys and the car would start easily from
then on. On another, the points were not opening, or were barely
opening. On the last, the car was actually getting bloody hot --
the temp gauge would jump into the red when the motor was turned off
and at idle the temp gauge would be at 3/5ths. That car had a warped
intake/exhaust manifold which I had skimmed smooth and I also
removed the secondary butterfly valves. In each case, even on
really hot days the cars would run okay after I fixed the problems.
chris