Severe fever with chills and frequent loose motions is most often caused by a significant stomach or intestinal infection, and sometimes by food or water contamination, so the most important step is to prevent dehydration and seek proper medical care. Drink plenty of fluids like oral rehydration solution (ORS), clean water, coconut water, or clear soups in small, frequent sips, as the body loses a lot of water and salts through diarrhoea and fever. Eat light, easily digestible foods such as rice, curd, bananas, khichdi, toast, or boiled vegetables, and avoid oily, spicy, and outside food until recovery. Paracetamol can help reduce fever and body aches, but it should be taken in the correct dose and not overused. Do not take antibiotics or strong anti-diarrheal medicines on your own, as the treatment depends on the exact cause of infection. You should consult a doctor urgently if the fever is very high, chills are severe, there is blood in the stools, persistent vomiting, severe abdominal pain, signs of dehydration like dizziness or reduced urination, or if symptoms continue beyond 1-2 days without improvement. In some cases, stool tests or blood tests may be needed to identify the infection and guide proper treatment. With timely care, fluids, rest, and correct medication when needed, most people recover well.