I had this same problem, ND is correct!! Toggling thru Menu is too slow for this
else you'll get zapped..
I used invisibility until I passed a Stone Monster & hid behind large rock on nearby island. Rested until Meter recharged.
LavaGaurdian can see you,but his little minions can't, so he won't send them if you are invisible or hiding behind something.
..Course its fun 'shooting them critters with Indys' .45 cal.
I use a combo of Joystick and keyboard.