There are many reasons that cause coldness on the body, such as cold air, female menstruation, malnutrition, fever, hypothyroidism, etc. 1. Cold air: A low outside environment and thin clothes will cause the body to become cold, which will lead to coldness on the body. 2. Female menstruation: Vaginal bleeding during female menstruation will cause a decrease in immunity, which may result in chills on the body. 3. Malnutrition: anemia, lack of vitamins, lack of trace elements, etc. may also lead to chills. 4. Fever: Fever caused by various reasons, chills may occur when the body temperature is rising, and some may cause chills and shivering. 5. Hypothyroidism: Insufficient secretion of thyroxine causes hypothyroidism, which leads to slower metabolism and insufficient heat production, and may also be manifested as chills. There may be other causes of chills, so you need to go to the hospital and follow the doctor’s instructions.