if you could place the container east of some shade trees or a building it would help some.  you could also cut a hole in the back for a powered vent that would kick on if it was over 85-90.  make sure there are plenty of shipping container air vents, you can add more cheaply.  https://www.amazon.com/Mytee-Products-Shipping-Container-Ventilation/dp/B0B5N9ZFFZ/ref=asc_df_B0B5N9ZFFZ?tag=bngsmtphsnus-20&linkCode=df0&hvadid=80814222102182&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584413756011005&th=1  
 
https://www.amazon.com/Solar-RoofBlaster-for-Conex-Containers/dp/B088G29CQ8/ref=pd_lpo_sccl_3/134-9764394-5640157?pd_rd_w=te8Yz&content-id=amzn1.sym.1ad2066f-97d2-4731-9356-36b3edf1ae04&pf_rd_p=1ad2066f-97d2-4731-9356-36b3edf1ae04&pf_rd_r=7P5N9EN79NQEDEP33S0M&pd_rd_wg=3TfM6&pd_rd_r=f1a3b038-4ca2-483c-ae65-146c61a2f5c5&pd_rd_i=B088G29CQ8&psc=1