In the 80s - 90s his CDs probably were commercial "pressed" disks, with the data imprinted as molded mechanical pits. The most likely disk material, probably polycarbonate(?), would not melt at as low a temperature as the vinyl used in many LPs of the same period, but would warp at only slightly higher temperatures.

For CDs made as home recordings, the data is in a "photosensitive" chemical layer that isn't likely to survive much exposure to any "energetically active environment."

I've seen one instance where a "house fire" left water standing in a glass on the table three feet below a common 60W light bulb in which the glass envelope of the bulb was melted and the "bulb" sagged to about 9" long. (The fire inspector pointed out that the bulb looked more like some bizarre sex toy than like a light bulb.) It's very difficult in such cases, especially for "house fires," to support any argument that everything in the fire was exposed to the same - or even to similar - temperatures.

Any "warm" temperature uncomfortable for you to be in for long periods is not a good place to keep either vinyl or CD recordings. Temperatures that don't produce obvious damage during short exposures will still degrade or destroy the data on CDs if the same conditions persist over longer times.

John