My 8yo son slipped on the stairs coming down, He fell several steps and appears to have fallen heavily. No witnesses. He has a big red mark on his back. Unfortunately, he had just finished eating an apple which came back up and prevented him from breathing for a very short while before he spat it out the undigested apple. This put him in a state. He is now complaining of chest pains on his sternum some 20 minutes later.