NORSE, including FIRES, occurs when a person without a previous history of seizures experiences sudden, prolonged seizures (status epilepticus) without a clear cause identified within the first 72 hours of presentation. The first symptoms of NORSE, including FIRES, typically include a mild fever and general illness; people may also experience behavioral or cognitive symptoms. Diagnostics may include brain imaging, cerebrospinal fluid studies, and blood tests. A diagnosis of NORSE, including FIRES, is suspected in patients who develop status epilepticus that does not respond to at least two antiseizure medications and does not have an identified cause. NORSE, including FIRES, is an uncommon condition but is associated with significant long-term morbidity and mortality. Most survivors develop multidrug-resistant epilepsy and have significant cognitive and functional impairment.