On 23 Oct 2009 the first author found 4 small ticks (~2 mm in length) engorged and attached to his left leg after conducting 2 days of field work in Citra (UF-PSREU, Marion County, FL) and Cross Creek (Lochloosa Wildlife Conservation Area, Alachua County, FL). Two of the specimens were preserved in alcohol. Nine days later (1 Nov) he developed a low-grade fever. By 7 Nov he began to experience minor myalgia (muscle pain) and intensifying cycles of fever, chills, and sweating, which were no longer controlled with ibuprofen. Assuming it was influenza, because of the recent outbreaks, he delayed seeking medical attention. On 9 Nov his spouse (a physician, the second author) took him to the emergency room of a Broward County FL hospital, where he presented with generalized “flu-like” symptoms—a fever of 38.9°C (102°F), frontal-temporal headaches, backaches, and malaise. A rapid diagnostic test for novel influenza A (H1N1) was negative, and he was admitted to the ICU for a fulminant (sudden and severe) febrile illness of unknown cause. Initial tests indicated severe thrombocytopenia (low platelets), moderate leukocytopenia (low white blood cells), elevated liver enzymes, and dehydration. That evening, the scientist contacted his senior technician and requested that the tick specimens be photographed and sent to a medical entomologist for identification. By the next day, they were identified as nymphs of the lone star tick, Amblyomma americanum L. (Acari: Ixodidae) (Fig. 1). Alerted to the possibility of a tick-borne illness, physicians started the patient on intravenous doxycycline, a broad spectrum tetracycline antibiotic. Over the next few days paroxysmal high fevers persisted, spiking to 40°C (104°F), and the patient’s condition deteriorated to a moribund state. Imaging techniques (CT scan, ultrasound, X-ray) revealed pleural effusion (fluid in the chest cavity) and hepatomegaly (enlarged liver). The patient developed respiratory distress, anemia, intense myalgia and arthralgia (joint pain), nausea, and a blotchy rash that started on the back and spread to the ventral trunk. On day 5 post-admission (13 Nov), the fever finally subsided and the patient began to show improvement. During the 11-d hospitalization (the first 7 in ICU), doctors ruled out numerous viral infections (e.g., influenza strains, HIV, Epstein-Barr, cytomegalovirus) and blood disorders (e.g., leukemia, lymphoma). Blood samples were sent to several reference laboratories to test for vector-borne pathogens, and negative results were obtained for the pathogens causing Lyme disease, typhus, encephalitis, dengue, malaria, and West Nile virus. On d 8 of hospitalization, positive results (indirect immunofluoresence assay, State Health Laboratory,