My party (lvl 7; Rogue, Cleric, Fighter, Paladin and Warlock) is investigating a demon portal, and we try to obtain as much info as possible before entering it. We learned that it is kept open by the magical force of something or someone, and it will probably close when we destroy that person or object. We've come to believe that the object might be the heart of an NPC. To make a long story short, she was cursed to do stuff for an evil God, and probably summoned some demons right before we broke the curse. Those demons opened the gate, but the NPC doesn't remember specifics of the time she was cursed, probably to repress all the horrible things she did with undead and stuff.
We felt her pulse, and she has none. But still, my party is in doubt - it might be because she has no heart, or it might be that she has a heart but it is just not beating.
Here an interesting discussion started regarding the use of Locate Object, with the conclusion that officially it is probably not allowed, but the rule of cool might apply.
This left me to wonder, what other methods would be available to a 7th level party to determine whether a (human) create has his/her heart on the right place (literally) which would not kill/do permanent damage to the creature?