Despite Bob's criticism, I had another thought about this...

If the negative material was highly flexible and sticky, you could adhere it really well to your skin and get good contact so that one could actually come away with a decent image by the end of the day. Maybe it could be a thin collodion "stripping film", that after processing could be stripped off its base, wetted and plastered onto your skin. The same idea could potentially work with gelatin. You could "fix" your image by applying a liberal amount of high SPF sunscreen.

Thinking about matching H&D curves to your skin's burning "curve" is rather amusing...