Chills and sweating: possible causes

Sweating cools the skin while shivering generates heat, so the two sensations can occur during a temperature shift. A warm room, exercise, anxiety, alcohol, hormonal changes or a low blood sugar level may trigger them. Infection can also cause alternating chills and sweating; influenza, malaria, dengue fever, pneumonia, a urinary tract infection or kidney infection may have additional symptoms. A person can feel chilled while sweating without having recorded a fever.

Pay attention to timing and context. Note whether sweating is at night, whether clothes or bedding become soaked, and whether you have pain, cough, urinary symptoms, vomiting, rash or recent travel.

Move somewhere comfortable, remove damp layers, drink fluids and check your temperature. If diabetes or missed meals could be relevant, follow your personal low-blood-sugar plan. Do not drive if you feel faint or confused. Arrange a review when episodes recur, disrupt sleep, cause dehydration or occur with infection symptoms. A clinician may need to examine you and review medicines, glucose, hormones or possible infection.

Get urgent help for confusion, fainting, severe weakness, breathlessness, chest pain, cold clammy skin, a very fast heartbeat or rapidly worsening illness. Seek prompt advice for persistent vomiting, flank pain, painful urination, severe headache, rash or recent malaria-area travel. Sweating can make fever harder to recognise, so do not use the absence of a reading to dismiss serious symptoms.

Ask whether the episodes could relate to infection, blood sugar, hormones, medicines or anxiety, and what information would help identify the trigger.