Suggest Treatment For Fever With Body Aches,chills And Sore Teeth

My mother and I share an odd characteristic. Whenever we're sick with a fever and all it's accompanying symptoms; muscle aches, chills, sore teeth, aching eyes, fatigue, etc. our temperature never rises above 99 degrees fahrenheit. It's hard to get doctors to believe we're actually sick without a thermometer telling them we have a high number. What's the cause of our odd characteristic?