Have you ever seen a child in your emergency department with a fever - he asks sarcastically? At the ginormous community hospital where I work, we see about 25,000 kids each year in our ED and about half of them present with fever. Yes, there still exists fever phobia in our society, which brings hoards of worried parents into the ED with their febrile kids. For most of these kids it's relatively straight forward: Most kids with fever have clinical evidence of an identifiable source of infection – a viral respiratory infection, acute otitis media, gastro, or a viral exanthem. However, about 20% have Fever Without a Source despite your thorough history and physical exam. A small but significant number of this 20% without an identifiable source of fever will have an occult bacterial infection - UTI, bacteremia, pneumonia, or even the dreaded early bacterial meningitis. These are all defined as Serious Bacterial Infections (SBI), with occult UTI being the most common SBI especially in children under the age of 2 years. In the old days we used to do a full septic work-up including LP for all infants under the age of 3 months, but thankfully, times have changed in the post-Hib and pneumoccocal vaccine age, and we aren’t quite so aggressive any more with our work-ups. Nonetheless, it's still controversial as to which kids need a full septic workup, which kids need a partial septic workup, which kids need just a urine dip and which kids need little except to reassure the parents. In this episode, with the help of Dr. Sarah Reid and Dr. Gina Neto from the Children's Hospital of Eastern Ontario, we will elucidate how to deal with fever phobia, when a rectal temp is necessary, how to pick out the kids with fever that we need to worry about, how to work up kids with fever depending on their age, risk factors and clinical picture, who needs a urinalysis, who needs a CXR, who needs blood cultures and who needs an LP, and much more....