I'll arrive to Jfk at 6 a.m. from L.A (British Airways flight - terminal 4); then I'll depart from Jfk to Milan (Italy) at about 6 p.m of the same day.
I think to leave our luggagem exit from Jfk, go to Manhattan, spend some hours and then come back "in time" for the next flight.
Do you think is possible? There's luggage deposit at 4th Terminal?
Thank you
Roberto
JFK Airport Guide
Luggage deposit