I'm not sure what your care provider has in mind when saying fever was causing palpitations. It seems to me palpitation and fever are concomitant signs for an underlying cause that should be diagnosed. For instance myocarditis (inflammation of heart muscle) is a viral infection or bacterial infection. Common symptoms of myocarditis include fever, joint pains, palpitations, rapid pulse, and chest pain. There are many underlying causes that have a low fever and heart palpitiations. There can be a thyroid problem, pulmonary embolism (blood clots in the respiratory system), etc.
Thanks for the question, hope it provides a perspective that will enable you to further discuss the matter with your doctor. If you have any further questions or comments you are welcome to respond. Take care,
Ken