失温症

title: 症状.
content: 人体的正常体温是36.5–37.5 °C(97.7–99.5 °F)。低体温症根据其严重程度可分为三期。  体温降至比正常体温低1-2 °C(1.8-3.6 °F)。在这一阶段,人体会产生颤抖,双手麻木,无法完成复杂动作。远端肢体血管收缩,以减少热量散失。呼吸快而浅。皮肤上出现“鸡皮疙瘩”,尝试使毛发竖立起来形成隔热层(人体由于毛发不足,这一反应作用有限,但是在其他物种中作用较大)。病人可能感觉疲劳和腹部疼痛。病人会有温暖的感觉,但事实上这是低体温症发展到第二期的信号。一种测试病情向第二期发展程度的方法是病人能否使拇指和小指接触,这是肌肉停止工作的第一阶段。病人可能会有视力困难。  体温降至比正常体温低2-4 °C(3.8-7.6 °F)。颤抖更猛烈。肌肉不协调更明显。行动更迟缓、困难,伴有步伐跌跌撞撞、方向混乱,尽管病人可能保持警觉。浅层血管继续收缩,以保持重要器官的温度。病人面色苍白,唇、耳、手指和脚趾可能变蓝。  体温降至大约32 °C(89.6 °F)以下。颤抖通常已停止。语言有困难,思维迟钝,记忆开始出现问题。通常手已经不能使用,行走经常跌倒。细胞新陈代谢停止。体温降至30 °C(86.0 °F)以下时,暴露的皮肤变蓝、涨大,肌肉协调能力几乎完全丧失,行走几乎不可能,语无伦次、行动毫无理性(包括可能尝试钻进洞里),甚至昏迷。脉搏和呼吸显著减慢,但是可能发生心率过快(心室性心搏过速和心房纤维性颤动)。主要器官停止工作,宣告临床死亡。由于细胞活动降低,一段时间之后脑死亡才会发生。
title: 处置方法.
content: 多穿衣服、棉被为身体保温,但衣服,棉被并不能增加热量,只起到减少热量流失的作用。所以,遇到寒冷天气应当立刻穿上衣服,盖上棉被,否则如果到了第三周期后很难调节体温了。  同时在第一周期时,建议进行适当运动防止人体温度散失过快,做运动可以增加热量。但是如果人体温度持续下降应立刻停止运动并且向周边进行求助。  亦有一种「快速启动回温法」(Rapid Active Rewarming),是迄今最有效的治疗方法,西方国家也大量采用这个方法,但讽刺的是,这是在纳粹德国对犹太人的纳粹人体实验得知的治疗方式。
title: 预防.
content: 冬天外出时多穿衣服,如出现以上症状,立即求助或拨打急救电话。

Summary: 失温症(英语:Hypothermia,源自希腊文「」),又称低温症、低体温症。描述当人体核心温度低于时的现象。失温症的症状取决于温度,轻度失温可能造成发抖与意识混浊;中度失温的发抖症状消失,但精神错乱的状况则会加剧。在重度失温的情况下,会有反常脱衣现象,也就是患者开始脱去衣物,这也同时增加了心搏停止的风险。 失温症主要有两个造成原因,第一个最常见的是暴露在极低温的环境中,也有可能是处于任何一种会抑制体内产热机制或增加失温速度的情况下。这种状态,多和酒精中毒脱不了关系,但可能在患有低血糖、厌食症、年老与其他不明原因下促使失温症的产生。体温调节的恒定机转理应将身体温度维持在间。颤抖、增加自发性运动的频率以及穿上温暖的衣物都有助于提高体内温度。失温症的诊断主要是依据评估患者当下所处环境中危险因子可能引发的各项病征,或是借由量测病人的核心温度所获得。 轻微的失温症可以用热饮料、穿着暖和衣服及身体活动来改善。若是中等程度的的失温症,建议使用加热毯及注射加热过后的静脉输液。中等或是严重的失温症病患需小心的移动。严重的失温症病患可以用体外心肺循环或是体外膜氧合(ECMO)。若已没有脉搏需同时进行心肺复苏(CPR)。病人的复温需持续到其体温超过为止。若此时病情仍没有改善,或是过程中血钾浓度高于12 mmol/liter,此时可以停止心肺复苏术。 美国每年大约有1,500人因失温症而丧生,患者多为老年人与男性。目前记录中,失温症患者所能达到的最低温度是一名在瑞典因溺水而造成失温的7岁女孩,她当时的体温为,急救记录中描述在经过超过六个小时的心肺复苏术(CPR)后她成功存活下来。若过程中使用叶克膜或绕道手术,存活率大约是50%左右。战争中,失温症常常是造成士兵死亡的重要死因。和失温症相对的症状是高热,该疾病的成因是由于体内温度的调节系统失常而使得体温不正常的升高。

Hypothermia: Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe hypothermia, there may be paradoxical undressing, in which a person removes their clothing, as well as an increased risk of the heart stopping. Hypothermia has two main types of causes. It classically occurs from exposure to extreme cold. It may also occur from any condition that decreases heat production or increases heat loss. Commonly this includes alcohol intoxication but may also include low blood sugar, anorexia, and advanced age. Body temperature is usually maintained near a constant level of through thermoregulation. Efforts to increase body temperature involve shivering, increased voluntary activity, and putting on warmer clothing. Hypothermia may be diagnosed based on either a person's symptoms in the presence of risk factors or by measuring a person's core temperature. The treatment of mild hypothermia involves warm drinks, warm clothing, and physical activity. In those with moderate hypothermia, heating blankets and warmed intravenous fluids are recommended. People with moderate or severe hypothermia should be moved gently. In severe hypothermia, extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass may be useful. In those without a pulse, cardiopulmonary resuscitation (CPR) is indicated along with the above measures. Rewarming is typically continued until a person's temperature is greater than. If there is no improvement at this point or the blood potassium level is greater than 12 mmol/liter at any time, resuscitation may be discontinued. Hypothermia is the cause of at least 1,500 deaths a year in the United States. It is more common in older people and males. One of the lowest documented body temperatures from which someone with accidental hypothermia has survived is in a near-drowning of a 7-year-old girl in Sweden. Survival after more than six hours of CPR has been described. In individuals for whom ECMO or bypass is used, survival is around 50%. Deaths due to hypothermia have played an important role in many wars. The term is from Greek ὑπο, "hupo", meaning "under", and θερμία, "thermía", meaning "heat". The opposite of hypothermia is hyperthermia, an increased body temperature due to failed thermoregulation.