[Taf]

What Chris said, many high current switches now come with double screw fixers that help reduce the heating risk.

But beware that even connecting or disconnecting a bayonet-fitting gas pipe is now required to be done by a Gas Safe engineer. Money for old rope, but it's now a requirement.

Also note that many electric cookers now come WITHOUT a mains lead as the actual connecting-up can be frought with legal problems through regulations.