What should you know about sudden shivering at night without fever?

Shivering is rapid muscle activity that generates heat. A cool room, damp clothing, a nightmare, anxiety or a sudden stress response can trigger it without fever. Low blood sugar may cause shaking with sweating, hunger, palpitations or weakness, especially in someone using diabetes medicine. An infection can begin before a fever is measurable; Influenza, Pneumonia, Urinary Tract Infection and Kidney Infection may bring chills with cough, pain, urinary symptoms or feeling unwell. Malaria and Dengue Fever matter after relevant travel or mosquito exposure.

The absence of fever at one check does not rule out illness. Temperature readings can vary with timing, device and recent paracetamol or other fever-reducing medicine.

Warm yourself gradually, change out of damp clothing and check the room temperature. Measure your temperature again after resting, and record associated symptoms and recent travel. If you have diabetes, follow your personal low-blood-sugar plan and seek advice if symptoms do not settle. Drink fluids when able, but avoid alcohol as a way to feel warm. Arrange medical advice if episodes recur, disturb sleep or occur with urinary, respiratory or abdominal symptoms.

Get urgent help for confusion, fainting, extreme weakness, fast breathing, severe breathlessness, blue lips, a stiff neck, a new rash, severe pain or difficulty staying awake. Chills with a rapidly worsening illness can be a warning sign of Sepsis and should not be managed at home. Seek prompt assessment after travel to a malaria area, even if the first temperature reading is normal.

Could this relate to blood sugar, medication, infection or travel? Which symptoms should I monitor overnight? Do I need urine, blood or other tests if the shivering returns?