Can you sunburn under the amazon rain forest?

Question

or would the shade of the trees prevent you from getting burn

Answer 1

I would think that  the trees  would provide lush shade.

Answer 2

Yes, you can.  Although you have a canopy there, light does filter through.  While the rays that hit you may not be those of the visible range (when blocked form a shadow), UV rays are able to bounce more easily off of leaves.  Just to be on the safe side, you should where sunblock.