Neon or incandescent lamp, temperature more limited by the holder that you use for them, so you are kind of stuck on using a metal and glass lamp holder for them. No plastic on them, unless you have bakelite, which even then will suffer from degadation with time, thus you need ones with ceramic insulators. normally this is a neon lamp, with associated resistor, which can easily withstand the temperature, though the connections between the lamp, resistor and the wires are going to need to be crimped uninsulated connections, with glass fibre sleeving over them, and high temperature glass fibre sleeved wire to apply power to them.