cable routing

[tangod]

Most of my cables for fuse box supplies etc are in as being ex rac I'm reusing them.

Some I had to extend, good bit if solder and heat shrink as I don't want any crimp connections to worry about.

But on a mild day like today the cavity under roof where my cables where was surprisingly warm and on a hot day I would assume red hot.
Now after insulation etc this will get worse.

So my question is has anyone experienced problems with the heat and cabling?

Thanks