Shivering without feeling cold can happen for various reasons beyond just exposure to cold temperatures. It may be caused by factors such as anxiety or stress, low blood sugar (hypoglycemia), thyroid problems (especially hypothyroidism), anemia, certain medications, panic attacks, dehydration, hormonal imbalances, or infections even before a fever develops. Sometimes, shivering is triggered by internal body responses like an adrenaline rush or the body's attempt to regulate temperature despite not feeling cold externally. In these cases, the body is involuntarily causing muscles to contract and relax quickly to generate heat or respond to other physiological triggers. For example, stress leads to adrenaline release, which can cause muscle trembling. Low blood sugar triggers hormone releases that cause shivering. Thyroid problems slow metabolism, leading to feelings of chilliness without external cold. Infections may cause shivering as the body tries to raise its internal temperature before a fever sets in. Thus, shivering without feeling cold is a natural body response that can signal underlying health issues such as stress, metabolic changes, or infections, rather than just external temperature changes.