Random shutdown on MacBook

There have been several posts about this issue. Press the On/Off button for maybe 5 seconds then let it reboot. Failing that, what may help is to put the computer in the fridge for an hour. It likes being cold. I did it a few times earlier this year over the course of maybe two weeks. After each time, it seemed to stay working for longer than before, giving me the chance to transfer important files to a desktop. Then it worked fine for several months, till last week it did it again several times in a single day. So, I put it in the fridge for a couple of hours and it now seems to be okay again. Another "fix" is to work with it on an ice-pack. All along, just watch out for condensation.