I Have Pain In The Middle Under The Rib Cage.

I have pain in the middle under the rib cage. Then the pain goes to my back I get the chills so bad I'm shaking and can't get warm. I get short of breath, it he next day all the pain and chills are gone but I am exhausted, I did not want to call 911. I was out mowing lawn earlier in the day and the sun was not really out