My son aged about 17 years is suffering from fever from past 12 days. It started with headache and leg pain and the legs and hands were cold before the onset of fever and one more thing is that it is increasing, as on day one it was 98.8, then 100.6, yesterday it was 100.4 and today it is 102.1… First day I gave crocin pain reliever,  and yesterday  I gave Dolo 650 every six hours, the fever is not decreasing and today it is 102.1 and he also has tiredness.  Can anyone tell me what might be the reason for this type of fever? Got dengue test, it is negative Got typhoid test, it is negative Got malaria test, it is negative Got Weil Felix test, it is negative From yesterday night started Advent 1 gm , two doses are over,  one at night and one in morning,  and according to fever chart, the fever is not coming under control and it is increasing Please help... Thank you