Got it to work!
I'll share my code for others that may be interested for I have not seen this in the search results turn up.
:state=0:hudreset,hudx=50,hudy=10,hudimagefine=languagebank\english\gamecore\huds\hidden.png,hudname=hidden,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=10,hudimagefine=languagebank\english\gamecore\huds\danger.png,hudname=danger,hudhide=1,hudmake=display,state=10
:state=10,plriscrouching:hudreset,hudshow=hidden,hudunshow=danger,state=11
:state=11,plrnotcrouching:hudreset,hudunshow=hidden,hudshow=danger,state=10