When Jack gets on the bus for his long ride home he was experiencing a fever and feeling dizzy.
Hit the Bed
When Jack gets home he goes right to his bed and lays down and his specific defense (immune system) begins to do its job. It sends B cells to create antibodies to protect his body from the virus thats causing the fever. He is also having inflammation in his throat as he is having a hard time swallowing and he has mucus in his throat.
Jack's mom calls the doctor to come to the house and the doctor determines that Jack got bacteria from his food that he ate in his lunch and also by touching the garbage container. He explained to Jack that his Phagocyte cells are protecting his body from the harmful bacteria.