Special Operations medical provider must be familiar with the differential diagnosis for a patient with altered mental status since it includes multiple life-threatening illnesses. Potential diagnoses include meningitis, encephalitis, malaria and many others. While preparing to evacuate to definitive care from an austere location, they must also be prepared to initiate empiric therapy that is specific to the patient and the area of operations. We present a case of a U.S. Army Special Forces Soldier that developed limbic encephalitis of presumed Herpes Simplex Virus (HSV) origin. We will review the key differential diagnoses for this presentation with a focus on infectious etiologies. We will also summarize current diagnostic and therapeutic strategies. Our recommendation is to initiate oral acyclovir when IV acyclovir is not available and this diagnosis cannot be excluded.