Hypothermia Author: Dmitri Guvakov, MD, PhD; Stuart Weiss, MD, PhD; Albert Cheung, MD
Module updated - 2011-03-28
Author information and module status
Prevention
Screening
Diagnosis
Consultation for Diagnosis
Hospitalization
Non-drug Therapy
Drug Therapy
Patient Education
Consultation for Management
Follow-up
Tables
Figures
References
Glossary
What's New
Patient Information
Additional Resources
Tools
Diagnosis
  • Attempt to characterize circumstances of the patient's immediate illness and to identify risk factors for development of hypothermia, although a history may be difficult or impossible to obtain.
  • In patients with suspected hypothermia, measure core body temperature.
  • Classify hypothermia as mild, moderate, or severe.
  • Recognize the pitfalls in evaluating patients with severe hypothermia who may initially appear as cold and lifeless.
  • Obtain additional lab tests to assess the severity of associated metabolic imbalances and organ dysfunction.
  • Determine whether the hypothermia was primary or secondary that developed as a consequence of an underlying condition.
History and Physical Examination Elements of Hypothermia (table)
Laboratory and Other Studies for Hypothermia (table)
Differential Diagnosis of Hypothermia (table)

Attempt to characterize circumstances of the patient's immediate illness and to identify risk factors for development of hypothermia, although a history may be difficult or impossible to obtain. BC

  • Question witnesses, companions, and family members expeditiously about pertinent medical history if the patient is unable to provide a medical history.
  • Recognize the following major risk factors for hypothermia:
    • Cold exposure
    • Extremes of age
    • Trauma
    • Drug and alcohol use
    • Extensive inflammatory dermatologic conditions (eczema, psoriasis)
    • Endocrinopathies
    • Neurologic and psychiatric disease
    • Multisystem disease, such as sepsis or shock
  • See table History and Physical Examination Elements of Hypothermia.
Background | Back to top


In patients with suspected hypothermia, measure core body temperature. B

  • Determine the most accurate measurement of the core temperature in one of the following locations, in order of preference:
    • Rectum or bladder (Foley temperature probe)
    • Nasopharynx
    • Esophagus
    • Oral pharynx
    • Tympanic
    • Axilla
  • Measure skin temperature to determine the gradient between the core and shell (skin or surface) temperatures.
  • See table History and Physical Examination Elements of Hypothermia.
Background | Back to top


Classify hypothermia as mild, moderate, or severe. AB

  • Use a classification scheme like the one proposed and adopted by the American Heart Association, which uses measurements of core body temperatures:
    • Mild: core temperature 36 to 34°C (96.8 to 93.2°F)
    • Moderate: core temperature 34 to 30°C (93.2 to 86°F)
    • Severe: core temperature <30 (<86°F) associated with markedly decreased cerebral blood flow, oxygen requirement, cardiac output and arterial pressure
  • See table History and Physical Examination Elements of Hypothermia.
Background | Back to top


Recognize the pitfalls in evaluating patients with severe hypothermia who may initially appear as cold and lifeless. B

  • Understand that hypothermic patients may initially appear deceased, but are still alive; patients with severe hypothermia may have shallow respirations and a weak bradycardic pulse that may seem absent.
  • Examine the hypothermic patients as gently as possible, avoiding any rough movements.
  • Consider using needle electrodes to improve electrical contact for electrocardiography.
  • Provide severely hypothermic patients with hemodynamic support until they are rewarmed to 35°C (95°F) before rendering diagnosis of death.
  • See table History and Physical Examination Elements of Hypothermia.
Background | Back to top


Obtain additional lab tests to assess the severity of associated metabolic imbalances and organ dysfunction. B

Background | Back to top


Determine whether the hypothermia was primary or secondary that developed as a consequence of an underlying condition. B

  • Recognize the various clinical manifestations of hypothermia by a systematic approach:
    • Neurologic:
      • Confusion
      • Impaired judgment, a nonspecific finding
    • Cardiovascular:
      • Initially vasoconstriction, tachycardia, and increased cardiac output
      • Progresses to myocardial depression, hypotension, and bradycardia
    • Renal:
      • Cold diuresis
      • Progresses to oliguria and renal insufficiency
    • Pulmonary:
      • Initial increase in respiratory rate
      • Progresses to depression of the respiratory center that is manifest as a decreased respiratory rate and progressive respiratory acidosis
    • Hematologic:
      • Increased blood viscosity
      • Hemoconcentration
      • Granulocytopenia
      • Abnormal coagulation profile (PT and activated PTT) at moderate hypothermia
    • Gastrointestinal:
      • Pancreatitis
      • Wischnewsky spots caused by bleeding within gastric glands
  • Treat hypothermia concurrently with any other underlying or contributing disease processes.
  • Differentiate end-organ manifestations of hypothermia from those of underlying diseases.
  • See table Differential Diagnosis of Hypothermia.
Background | Back to top

FAQs
Albert Cheung, MD has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations. Dmitri Guvakov, MD, PhD has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations. Stuart Weiss, MD, PhD has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations. Wenjun Martini, PhD, editorial consultant, has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations.
Deborah Korenstein, MD, FACP, Co-Editor, PIER, has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations. Richard B. Lynn, MD, FACP, Co-Editor, PIER, has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations.

The information included herein should never be used as a substitute for clinical judgment and does not represent an official position of ACP. Because all PIER modules are updated regularly, printed web pages or PDFs may rapidly become obsolete. Therefore, PIER users should compare the date of the last update on the website with any printout to ensure that the information being referred to is the most current available.
PIER is copyrighted © 2012 by the American College of Physicians,
190 N. Independence Mall West, Philadelphia, PA 19106-1572, USA.