Fever only colds?

Just wondering if anyone has had this with their lil ones? Dylan would get fairly high fevers for a few days, with no other symptoms, or when sometimes when he does get other colds, it is very short lived and symptoms are not all that bad. I think he has gotten these sicknesses from others who were really sick for a long time. So I chalk it up to a good immunse system??? Anyhow, Kaylee has gotten two fevers. The first one had very slight runny nose and a cough for a day. The last one that she just had she did not get any other symptoms. My thoughts are that they may get a virus, they body reacts to a quick temp raise, and kills it before it gets to bad??? I dont know, but the reason why I am asking is bc kaylee is having seizures. she has had three. The first one they thought maybe was a febrile (fever of 101) then with the slight cough/runny nose for the day, the second not sure, the third had another fever, for a few hours, but no cold symptoms, other then two coughs. I wonder if she is prone to seizures, if a virus hits her body, her body reacts, then goes hay wire with a seizure????
Anyhow, any other kids with good immune systems get a fever and not much of a cold after? The docs think i'm nuts when I tell them this (not like its a first time they look at me like i'm nuts). You know how strange we are, trying to keep our kids healthy naturally?