Mild therapeutic hypothermia can provide neuroprotection in some clinical situations (postanoxic cardiac arrest, neonatal anoxia). Techniques to induce hypothermia are based on thermal exchanges, in particular conduction and convection. There are several external cooling techniques: application of ice packs, cold moistened towel, ice-cold devices, ventilation of cooled air, water- or air-cooled circulating mattresses or devices. These techniques are frequently used because of their reduced cost. Internal cooling techniques are more limited and more expensive: ice-cold perfusion, endovascular catheters, extracorporeal circulation, but they offer more efficiency (high speed to reach and to maintain the temperature target). Drugs can also induce hypothermia, either by decreasing body temperature, e.g. paracetamol and aspirin, or by blocking shivering, e.g. neuromuscular blocking agents, opioids and alpha2-agonist.