My party (level 7; Rogue, Cleric, Fighter, Paladin, and Warlock) is investigating a demon portal, and we're trying to obtain as much info as possible before entering it. We learned that it is being 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 a particular NPC.
To make a long story short, the NPC 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 for 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.
In my original question (Can the Locate Object spell be used to determine if an NPC has a heart?), 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) creature has his/her heart in the right place (literally), without killing/doing permanent damage to the creature?