The max temperature parameter is in Kelvin. In the nosecone, in the part 58, you changed the max temperature to 100, or what's the same, -173ºC. Since the part is overheating from the moment you launch it starts taking damage until it explodes.
As stated in the tinker panel, those settings aren't fully supported, you use them at your own risk. If you run into problems check you haven't messed up anything in the tinker panel resetting everything to the stock values just in case.
The max temperature parameter is in Kelvin. In the nosecone, in the part 58, you changed the max temperature to 100, or what's the same, -173ºC. Since the part is overheating from the moment you launch it starts taking damage until it explodes.
As stated in the tinker panel, those settings aren't fully supported, you use them at your own risk. If you run into problems check you haven't messed up anything in the tinker panel resetting everything to the stock values just in case.