Fever and food poisoning: what to know

Food poisoning may irritate the stomach and bowel, causing abdominal cramps, nausea, loose stools, vomiting and a raised temperature. Fever is one possible presentation of food poisoning; it does not by itself identify the germ or show how severe the illness will become. Fluid loss from repeated vomiting, diarrhoea, sweating or fever can lead to dehydration, with thirst, a dry mouth, darker urine, dizziness or unusual tiredness.

Take frequent small sips of water or an oral rehydration drink. If vomiting settles, add simple foods in small portions and avoid alcohol and foods that worsen nausea. Rest, wash hands carefully, and avoid preparing food for other people while you are unwell. Do not use leftover antibiotics or anti-diarrhoeal medicine without suitable advice, because the choice depends on the illness and your health.

Arrange prompt medical advice if you cannot keep fluids down, have blood in vomit or stool, severe or localised abdominal pain, faintness, confusion, very little urine, or a fever that is worsening or not settling. Seek urgent help for difficulty breathing, collapse, marked drowsiness or signs of severe dehydration. Children, older adults, pregnant people and those with significant medical conditions may need earlier assessment.

Ask which fluids are suitable, whether you need testing, and which medicines are safe with your existing conditions. Tell the clinician when the symptoms began, what you ate, how often you have vomited or passed stool, and whether anyone else became ill.