The measures that you need to take to protect your physical health, is to take at least 10-15 minutes break after every 1-2 hours of being on the computer or else you can get RSI- Resistance Strain Injury.
For your safety you should make sure that your hands are not wet when you are switching on the computer switch, if it is, wipe your hands or you could get electrocuted.
To protect your files from getting lost you can save your files in more than 1 places with a suitable name that you can remember it by.
You could also save your files on your USB drive so that even if the files are lost in one place you can still find them in other places
- make sure you proceed with this process on a regular bases