Low doses of radiation in the form of chest X-rays have been used to treat people with pneumonia. This treatment was found to be effective by reducing inflammation and with minimal side effects. However, it was an expensive treatment and was eventually replaced with less costly treatments such as antibiotics. Radiation has also been shown in some animal experiments to reduce some types of inflammation. Some patients diagnosed with COVID-19 pneumonia will experience worsening disease, which can become very serious, requiring the use of a ventilator. This is caused by inflammation in the lung from the virus and the immune system. For this study, the x-ray given is called radiation therapy. Radiation therapy uses high-energy X-ray beams from a large machine to target the lungs and reduce inflammation. Usually, it is given at much higher doses to treat cancers. The purpose of this study is to find out if adding a single treatment of low-dose x-rays to the lungs might reduce the amount of inflammation in the lungs from a COVID-19 infection, which could help a patient to breathe without use of a ventilator.