Fever, in Influenza as well as dengue, is often abrupt onset and high grade. In influenza, the common accompanying symptoms include dry cough, severe myalgia, nasal symptoms, sore throat, and headache. In dengue, commonly associated symptoms include myalgia, body ache, headache (particularly retro-orbital area), skin rash, etc. In COVID-19, fever is usually low grade and can be associated with symptoms such as dry cough, myalgia, headache, smell and taste abnormalities, diarrhea, skin rash, conjunctivitis, etc.

from Times of India https://timesofindia.indiatimes.com/life-style/health-fitness/health-news/your-high-fever-isnt-covid-flu-or-dengue-signs-it-could-be-pneumonia/articleshow/94639614.cms