AAEM MINIMONOGRAPH # 14 Temperature affects biologic and neurophysiologic processes and is, therefore, always well controlled in in vitro experiments. Its role is equally important in the clinical laboratory but has often been neglected. Lower temperature cause slower nerve conduction velocities (NCVs), and increased amplitudes of muscle and nerve potentials. Fibrillations may disappear, and muscle contraction will be slower and weaker. Neuromuscular transmission improves. Somatosensory evoked potentials (SEPs) are similarly vulnerable in the peripheral segments, or with changes in central temperature. As a result, abnormalities are artificially created or existing defects are not detected, resulting in false or missed diagnoses. Control of temperature, albeit somewhat time consuming, will result in greater diagnostic accuracy.