Chills and feeling cold

Chills are involuntary muscle contractions that generate warmth; feeling cold can occur without visible shaking. Influenza, dengue fever, malaria, pneumonia, a urinary tract infection, or a kidney infection may present with chills, often alongside other symptoms. Sepsis can cause a person to feel very unwell and needs urgent attention. Low food intake, fluid loss, anxiety, or an underactive thyroid may also alter how warm you feel. The timing and accompanying symptoms provide useful clues.

Move to a comfortable environment, add a light layer, eat if you have missed meals, and drink fluids unless you have a fluid restriction. Measure your temperature with a reliable thermometer and repeat it if symptoms change. Rest and note cough, pain when passing urine, back pain, rash, vomiting, travel, and insect exposure. Avoid very hot baths if you feel dizzy, and do not self-treat a possible infection with leftover medicine.

Call emergency services for confusion, fainting, severe breathing difficulty, blue or clammy skin, a seizure, or sudden extreme weakness. Seek same-day assessment for persistent or worsening chills, a new fever, severe pain, rash, repeated vomiting, reduced urine, or symptoms after travel to a malaria-risk area. Prompt care matters if you feel rapidly more unwell, even before a temperature rises.

Could infection, dehydration, low blood sugar, or thyroid problems explain this? Which symptoms should I monitor at home? Do my medicines or recent travel change the assessment?