I have a shop lamp with a hook on the top and a cage around the bulb area. On the handle it says: 660W 250V. Would it be safe to put a infrared ceramic reptile heater type bulb in this light fixture? Thank you very much.
You can put a heating element up to 600 watts in that socket.
An incandescent light bulb puts out 10% to 20% light and the rest of the watts consumed becomes heat. The worst case heat scenario is a 660 watt bulb (if one existed) with the 10% light output which means 90% heat which comes out to about 600 watts of heat.
The 250 volt rating means that it could be used safely on a 240 volt circuit which is the standard household circuit in many other countries.
For those who haven't seen them or antique parabolic radiant space heaters, yes they did make ceramic cylinder elements with Nichrome or similar heating wire coiled around, and with a screw in light bulb type contact base.
It is difficult to shop locally when the locality slaps you with a fine if you are a little slow getting back to your car.