From what you mentioned, your childhood tachycardia looks more like a symptom/result of some allergic reaction. > When I exercise it almost immediately goes to

From what you mentioned, your childhood tachycardia looks more like a symptom/result of some allergic reaction. > When I exercise it almost immediately goes to the very high 100s, and sometimes to 200 after strenuous exercise At age 31, "immediately goes to the very high 100s" - if you go above 140 fairly quickly and you are not in endurance sports, it is concerning. You should consult a cardiologist when times get normal. Typically athletes involved in endurance sports also have lower than normal Rhr. > in terms of seeking care early For Covid19, because of its scale, you can't do much other than vaguely understanding the line of treatment and going to the hospital when symptoms appear. Do not think: "I will give it one more day". 90% covid19 infected people do not need a ventilator. When in doubt, get a test done. But note that the tests may result into a false negative if you appear without the symptoms. Do not panic. For future doctor visit, keep a fever record with time and comment any progression of symptoms. Stay hydrated and get enough rest.