What should you know about cold chills after eating?

Chills are an involuntary muscle response that can happen as the body adjusts its temperature. If fever, cough, body aches or fatigue follow, influenza or pneumonia may be developing. Burning urine, back pain or nausea can occur with a urinary tract or kidney infection. In regions where mosquito-borne illness is possible, malaria or dengue fever may also cause fever and chills. A reaction soon after eating with hives, swelling, vomiting or breathing trouble may be anaphylaxis and needs emergency care. Timing alone does not prove that food caused the chills.

Sit somewhere safe, take your temperature if possible, drink fluids and note what you ate, when symptoms began and any other symptoms. Rest and avoid preparing food for others if you have fever, vomiting or diarrhoea. Do not take leftover antibiotics or malaria medicines. If a particular food repeatedly causes symptoms, avoid it until a clinician has assessed the pattern; seek emergency help for breathing or swelling symptoms.

Get emergency help for difficulty breathing, throat or tongue swelling, fainting, confusion, severe weakness, blue lips or a rapidly spreading rash. Seek same-day medical care for shaking chills with a high fever, severe headache, stiff neck, chest pain, shortness of breath, persistent vomiting, severe abdominal or back pain, or very little urine. Arrange review if episodes recur or fever continues.

Could an infection, medicine or food reaction explain the timing? Do I need urine, blood or other tests? Which symptoms mean I should attend emergency care?