The very warm weather and personal experience brought the first hot tip and this page.
If you use a laptop sitting flat on a desk in hot weather, grab a wire baking tray and sit it on this It will allow the air to move more freely, keeping the laptop cooler, stopping it from turning itself off and losing all your unsaved data. They are also very shallow, so it won't affect the typing position too much either.
Storage is cheap, the delete key is forever - doesn't really need explaining, but means make and keep your back-ups, once deleted a memory is just that!
Always check the obvious things first, or sit down and think about the problem logically and work from a starting point to an end. Rather than going at it hit and miss.
I have an old NTSC VCR, I don't use it often as most people these days want dvds. I had to do a vhs for a customer and it wouldn't turn on... I tried everything I could think of. I gave up and left it. Next day, I sat down with a fresh mind and approached the problem from start to finish, and it took me one minute to find the problem.
Problem - no power.
I checked the fuse - OK.
I checked the power lead - it was split and one of the copper cables was broken!! Added a connector block to test, working!!