Look for bouts of shivering, accompanied by severe chill that cause chattering of teeth and "goose pimples" on the skin. This will be followed by rise in body temperature. It might go to 40.5 degree C. And accompanied by severe headaches, bodyaches, etc. This usually lasts for 4 to 6 hours after which the temperature declines, profuse sweating occurs, and the symptoms disappear, leaving a feeling of great weakness. But symptoms aren't always clear-cut. They might mimic other illnesses. Sometimes it is wrongly diagnosed as the flu. Or, as when it is accompanied by abdominal pain, vomiting, diarrhoea, it might be mistaken for a stomach upset. Plasmodium falciparum in particular exhibits symptoms of jaundice, convulsion, etc., and can be confused with gastroenteritis, hepatitis, meningitis or viral encephalitis.
Fever and high body temperature, chills, sweating, back pain, vomiting, diarrhoea, coma, flu, kidney failure, severe headaches, convulsion.