Hi, As I have answered previously in couple of questions, there can be various causes for nausea which include Chemicals or toxins, Motion sickness (disorder which cause nausea and vomiting in sensitive individuals while traveling), gastritis, peptic ulcer, severe hypertension, unpleasant smell or pictures, brain tumors, morning sickness, radiation therapy etc. As you are also chills and your body feels hot, there could be possibility of urinary tract infection or malaria or some other infection. If you were my patient, I would order investigations like CBC, complete urine examination, blood test to detect malarial parasites. Hope it helps!