Without the warning signals provided by thermal and pain stimuli, we don't react when our bodies are damaged.
如果没有体温或痛感的刺激来提醒我们引起注意，身体在受到损伤时，我们就不会做出相应的反应。
英语百科
Pain stimulus
Pain stimulus is a technique used by medical personnel for assessing the consciousness level of a person who is not responding to normal interaction, voice commands or gentle physical stimuli (such as shaking of the shoulders). It forms one part of a number of neurological assessments, including the first aid based AVPU scale and the more medically based Glasgow Coma Scale.