A high fever ~ that is, raising the temperature to make the body a less pleasant place for viruses and bacteria ~ is the first line of defence.
The nasal cannula refers to the "mask" or nasal tubes used to provide supplemental Oxygen to a patient.
It’s better not to. Coffee in general will effect your bloodwork, and it is no different with black coffee. This is due to the caffeine in it which might skew the results. It’s also a natural diuretic, so your bladder will not last as long.
Hope this was helpful!