If you're in a nasty situation (say, surrounded by a pack of raptors or lions, etc) then use a portable bed. It will instantly fill your hp, and after a couple seconds it'll shift to day or night which has the added effect of despawning everything around you.
I'm not sure what happens if you die while the screen is fading to black as I've only taken a few hits before it kicked in, but it's definitely a great "oh no" button. It also removes all of your poison to boot.
some beds would've been nice when i was trying my 100 year run with the porcupine... its BECAUSE i couldnt reset the area that i died... too many damn dinosaurs and lions having some massive war with each other around the last bit of territory i needed to capture. --- "You think you can just come here and attack us?" "You must be crazy, or just plain stupid!"-Meng Huo