Rajat is a ragpicker. He lives in a slum area located behind Reena's locality. Reena and Rajat play together in the evening. One day Reena couldn't find Rajat. She went to his home and saw he had a fever with chills and rigors. She took him to the clinic and he had a blood test. Reena gave him a special gift.
1. Fever with chills and rigors are the major symptoms of _____