Which step of the prices method is represented by the letter s?

I haven't heard of PRICES method. I only know of PRICE which stands for P  - protect
R  - rest
I    - ice
C  - compress
E  - elevate

However, since we are dealing with injuries, S can stand for SPLINT. You apply a splint on injuries with broken bones. This is to ensure that the edges of the broken bones will meld and mend together without any difficulty.