Temperature control in acute brain injury

Intensive Care Medicine: Published 20 April 2026

Purpose

Temperature is a key determinant of cerebral vulnerability after acute brain injury and a physiological variable that can be continuously monitored and actively controlled in the intensive care unit. Its therapeutic role has evolved from hypothermia-centred strategies toward early recognition of fever and controlled normothermia. This review examines the physiological rationale, clinical evidence, and contemporary practice of temperature management in neurocritical care.

Methods

We synthesised evidence from major randomised trials, observational studies, and international consensus recommendations across traumatic brain injury, acute vascular brain injury, and post-cardiac arrest encephalopathy, together with current monitoring and implementation approaches.

Results

Fever is consistently associated with worse neurological outcomes. In traumatic brain injury, hypothermia reduces intracranial pressure but does not improve functional outcome when used prophylactically and is reserved for refractory intracranial hypertension. In acute vascular brain injury, neutral trials and feasibility constraints have shifted practice toward early detection and treatment of fever rather than hypothermia. In post-cardiac arrest care, contemporary guidelines recommend protocolised temperature control with selection and maintenance of a constant target between 32°C and 37.5°C and active prevention of fever, rather than mandatory hypothermia.

Conclusions

Temperature control is a fundamental component of care aimed at protecting the injured brain through continuous monitoring, early detection of fever, and prevention of temperature-related harm.

 

 

Fever and hypothermia represent two populations of sepsis patients and are associated with outside temperature

 

by Daniel O. Thomas-Rüddel, Peter Hoffmann, Daniel Schwarzkopf, Christian Scheer, Friedhelm Bach, Marcus Komann, Herwig Gerlach, Manfred Weiss, Matthias Lindner, Hendrik Rüddel, Philipp Simon, Sven-Olaf Kuhn, Reinhard Wetzker, Michael Bauer, Konrad Reinhart and Frank Bloos 

 

Critical Care volume 25, Article number: 368 (2021) 

 

Background

Fever and hypothermia have been observed in septic patients. Their influence on prognosis is subject to ongoing debates.

Methods

We did a secondary analysis of a large clinical dataset from a quality improvement trial. A binary logistic regression model was calculated to assess the association of the thermal response with outcome and a multinomial regression model to assess factors associated with fever or hypothermia.

Results

With 6542 analyzable cases we observed a bimodal temperature response characterized by fever or hypothermia, normothermia was rare. Hypothermia and high fever were both associated with higher lactate values. Hypothermia was associated with higher mortality, but this association was reduced after adjustment for other risk factors. Age, community-acquired sepsis, lower BMI and lower outside temperatures were associated with hypothermia while bacteremia and higher procalcitonin values were associated with high fever.

Conclusions

Septic patients show either a hypothermic or a fever response. Whether hypothermia is a maladaptive response, as indicated by the higher mortality in hypothermic patients, or an adaptive response in patients with limited metabolic reserves under colder environmental conditions, remains an open question.

Fever in the Emergency Department Predicts Survival of Patients With Severe Sepsis and Septic Shock Admitted to the ICU

Fever in the Emergency Department Predicts Survival of Patients With Severe Sepsis and Septic Shock Admitted to the ICU
Sundén-Cullberg, J et al
Critical Care Medicine: April 2017 - Volume 45 - Issue 4 - p 591–599

Objectives: To study the prognostic value of fever in the emergency department in septic patients subsequently admitted to the ICU. Design: Observational cohort study from the Swedish national quality register for sepsis. Setting: Thirty ICU’s in Sweden. Patients: Two thousand two hundred twenty-five adults who were admitted to an ICU within 24 hours of hospital arrival with a diagnosis of severe sepsis or septic shock were included. Interventions: None. 
Measurements and Main Results: Body temperature was measured and classified according to four categories (< 37°C, 37–38.29°C, 38.3–39.5°C, ≥ 39.5°C). The main outcome was in-hospital mortality. Odds ratios for mortality according to body temperature were estimated using multivariable logistic regression. Subgroup analyses were conducted according to age, sex, underlying comorbidity, and time to given antibiotics. Overall mortality was 25%. More than half of patients had a body temperature below 38.3°C. Mortality was inversely correlated with temperature and decreased, on average, more than 5% points per °C increase, from 50% in those with the lowest temperatures to 9% in those with the highest. Increased body temperature in survivors was also associated with shorter hospital stays. Patients with fever received better quality of care, but the inverse association between body temperature and mortality was robust and remained consistent after adjustment for quality of care measures and other factors that could have confounded the association. Among vital signs, body temperature was best at predicting mortality. 
Conclusions: Contrary to common perceptions and current guidelines for care of critically ill septic patients, increased body temperature in the emergency department was strongly associated with lower mortality and shorter hospital stays in patients with severe sepsis or septic shock subsequently admitted to the ICU.

Effect of a fever control protocol-based strategy on ventilator-associated pneumonia in severely brain-injured patients

Effect of a fever control protocol-based strategy on ventilator-associated severely brain-injured patients. Critical Care 2014, 18: 689

Launey, Y., et al.

http://ccforum.com/content/pdf/s13054-014-0689-4.pdf

Fever is associated with a poor outcome in severely brain-injured patients, and its control is
one of the therapies used in this condition. But, fever suppression may promote infection, and
severely brain-injured patients are frequently exposed to infectious diseases, particularly
ventilator-associated pneumonia (VAP). Therefore, we designed a study to explore the role of
a fever control protocol in VAP development during neuro-intensive care.

Persistent fever in the ICU

Persistent fever in the ICU. Chest, Jan 2014, Vol. 145(1), p.158-165.

Rehman, T. and deBoisblanc, B.P.

http://journal.publications.chestnet.org/article.aspx?articleid=1793890

Disorders of elevated body temperature may be classified as either fever or hyperthermia. Fever is caused by a pyrogen-mediated upward adjustment of the hypothalamic thermostat; hyperthermia results from a loss of physiologic control of temperature regulation. Fever in the ICU can be due to infectious or noninfectious causes. 

Fever in adult ICUs

Fever in adult ICUs: An interrupted time series analysis. Critical care medicine, Aug 2013, Vol. 41(8), p.1863-69.  

Niven, D.J., et al.

http://journals.lww.com/ccmjournal/Abstract/2013/08000/Fever_in_Adult_ICUs___An_Interrupted_Time_Series.5.aspx

Fever is common and associated with increased mortality among patients admitted to adult ICUs, yet recent literature suggests that the incidence of fever may be decreasing. The objective of this study was to determine whether the incidence of fever in adult ICUs changed over time and the factors responsible for the observed change.

Fever in adult ICUs

Fever in adult ICUs: An interrupted time series analysis. Critical care medicine, August 2013, Vol. 41(8), p.1863-69.

Niven, D.J., et al.

http://journals.lww.com/ccmjournal/Abstract/2013/08000/Fever_in_Adult_ICUs___An_Interrupted_Time_Series.5.aspx

Fever is common and associated with increased mortality among patients admitted to adult ICUs, yet recent literature suggests that the incidence of fever may be decreasing. The objective of this study was to determine whether the incidence of fever in adult ICUs changed over time and the factors responsible for the observed change.

Fever in septic ICU patients: friend or foe?

Fever in septic ICU patients: friend or foe? Critical Care 2011 15:222

Launey Y., et al.

In recent years, fever control in critically ill patients by medications and/or external cooling has gained widespread use, notably in patients suffering from neurological injuries. Nevertheless, such a strategy in septic patients is not supported by relevant data. Indeed, in response to sepsis, experimental and clinical studies argue that fever plays a key role in increasing the clearance of microorganisms, the immune response and the heat shock response. Moreover, fever is a cornerstone diagnostic sign in clinical practice, which aids in early and appropriate therapy, and allows physicians to follow the infection course. After discussing the physiological aspects of fever production, this review aims to delineate the advantages and drawbacks of fever in septic patients.

Fever in septic ICU patients: friend or foe?

Fever in septic ICU patients: friend or foe? Critical Care 2011 15:222

Launey Y, Nesseler, N, Malledant Y and Seguin P.

In recent years, fever control in critically ill patients by medications and/or external cooling has gained widespread use, notably in patients suffering from neurological injuries. Nevertheless, such a strategy in septic patients is not supported by relevant data. Indeed, in response to sepsis, experimental and clinical studies argue that fever plays a key role in increasing the clearance of microorganisms, the immune response and the heat shock response. Moreover, fever is a cornerstone diagnostic sign in clinical practice, which aids in early and appropriate therapy, and allows physicians to follow the infection course. After discussing the physiological aspects of fever production, this review aims to delineate the advantages and drawbacks of fever in septic patients.

Relationships between fever and outcome in intensive care unit patients

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Kiekkas , P . ; Filos , K . S . ; Karanikolas , M . ; Aretha , D . ; Baltopoulos , G . I .
http://ovidsp.ovid.com/athens/ovidweb.cgi?T=JS&MODE=ovid&NEWS=n&PAGE=toc&D=ovft&AN=00003246-000000000-00000 Full Text (01/1995 - /)
Page: 3127 Vol/Issue: 2008 ; VOL 36 ; PART 11
ISSN Print: 0090-3493 E-ISSN: 1530-0293 Print Holdings: Yes
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Fever in critically ill patients
Chamorro , C . ; Romera , M . A . ; Balandin , B .
Ovid ( Journals @ Ovid ) via Athens Full Text (01/1995 - /)
Page: 3129-3129 Vol/Issue: 2008 ; VOL 36 ; PART 11
ISSN Print: 0090-3493 E-ISSN: 1530-0293 Print Holdings: Yes
Search Google: Article Author(s)