A warden said the prisoners destroyed light fixtures and surveillance cameras and flooded a gangway after being refused permission to wear shorts, which are forbidden in French prisons, Radio France International reported Friday.
Order at the Bourg-en-Bresse jail, in eastern France, was established after about 3 hours.
The disturbance Thursday ushered out the third-hottest July in France in more than a century. Temperatures over the previous 31 days had been as much as 16 degrees above average.
Temperatures in Lyon hit 93 degrees Fahrenheit Thursday. Paris recorded 95 degrees.
In an attempt to avoid repeating the large number of deaths recorded during the 2003 heat wave, the Paris city council has begun contacting 20,000 elderly or handicapped people who have indicated they want to be monitored when temperatures spike.
Overheated bus drivers in Marseilles decided to strike over their new uniforms, The Local.fr reported.
"I won't be wearing them," one driver said. "The shirts are all right, but these pants are far too tight."