Hope it's not PIH for you Sarah. Not sure about pretern care as I actually got it postnatally but I do have a good ring trick though.

Cool your hands as much as you can. Get a long piece of string. Tuck one end under the ring you want to remove (enough so you can grab it with the other hand). Wind the rest of the string around your finger so that each coil touches the last. Make it firm, but not tight enough to cut off circulation. Make it firm though so it compresses a bit.
Take the first end and just unwind with it still under the ring. The ring SHOULD come off with it.
Good luck