Acute Bronchitis: This is the most common cause of fever and cough, especially in the context of a recent upper respiratory infection. It's usually viral in nature and self-limiting.

Pneumonia: Both viral and bacterial pneumonia can present with fever and cough. The presence of other symptoms such as shortness of breath, chest pain, or sputum production can help differentiate it from bronchitis.
Influenza: Especially during flu season, influenza can cause fever, cough, and other systemic symptoms like body aches and fatigue.
Acute Sinusitis: If the cough is postnasal drip in nature, acute sinusitis could be a likely diagnosis, especially if accompanied by facial pain or headache.

Pulmonary Embolism: Although less common, pulmonary embolism can present with cough and fever, especially if there's associated chest pain or shortness of breath. It's critical to consider this diagnosis due to its high mortality rate if untreated.
Tuberculosis (TB): TB can present with chronic cough and fever, and it's essential to consider it, especially in high-risk populations or those with exposure history.
COVID-19: Given the current pandemic, COVID-19 should be considered in the differential diagnosis for anyone presenting with fever and cough, especially if there's a history of exposure or travel.

Sarcoidosis: A systemic disease that can affect the lungs, causing cough and fever among other symptoms. It's less common but should be considered in patients with persistent or unexplained symptoms.
Lung Cancer: Although rare as an initial presentation with fever and cough, lung cancer can cause these symptoms, especially in smokers or those with a significant smoking history.
Histoplasmosis or Coccidioidomycosis: Fungal infections that can cause fever, cough, and other respiratory symptoms, particularly in individuals who have traveled to or live in endemic areas.