Skip to main content

Body temperature correlates with mortality in COVID-19 patients

A Letter to this article was published on 24 July 2020

Systemic inflammation that accompanies acute respiratory distress syndrome in COVID-19 [1] is associated with a high mortality rate, as high as 32.5% [2]. Treatment options for severe cases remain limited [3]. The high mortality rate, lack of effective therapies, and extremely high volume of cases have led to a clear need for reliable prognostic markers to indicate which patients are at the highest risk of death and thus require closer monitoring.

One factor that is common to the majority of hospitalized COVID-19 patients is fever. The degree of temperature elevation might reflect the severity of inflammation. However, there are currently no published studies that have looked at body temperature (BT) as a potential prognostic marker. We sought to analyze how BT monitoring might inform mortality rate estimates in COVID-19-positive patients.

We analyzed BT data in the de-identified database of COVID-19-suspected patients in Mount Sinai and its affiliated hospitals in the New York area as of May 3, 2020. A total of 9417 patients tested positive for the SARS-CoV-2 virus by RT-PCR detection. After excluding patients with missing temperature data (n = 1802), 7614 patients were included in the analysis (Table 1). Fifty percent had a BT > 37 °C on the initial presentation and 78.5% of patients developed BT > 37 °C during the course of the disease. The overall mortality was 16.9% with a median of 7 days to death from the initial presentation. As shown in Fig. 1a, higher BT at the initial presentation did not show a significant association to mortality. Importantly, patients presenting with BT ≤ 36 °C had the highest mortality (26.5%, P = 0.003 relative to 36 °C < BT ≤ 37 °C), and this became even higher when the analysis was restricted to those with BT ≤ 35.5 °C (44%), indicating low body temperature at the initial presentation is a marker of poor prognosis. Meanwhile, maximum BT during COVID-19 infection was significantly correlated with mortality rate (Fig. 1b). There was a significant increase in mortality for every 0.5 °C increase in BT, and the mortality was as high as 42% in those with maximum BT > 40.0 °C.

Table 1 Characteristics of patients at first encounter
Fig. 1
figure 1

Body temperature and mortality in COVID-19 patients. a High body temperature at the initial presentation did not correlate significantly with mortality. Patients with BT ≤ 36 °C had significantly higher mortality compared to normothermia patients. b There was a significant increase in mortality for every 0.5 °C increase in maximum BT during the course of COVID-19 (Holms test)

Our results indicate that only half of the patients with positive SARS-CoV-2 virus present with BT > 37 °C at the initial presentation. However, temperature elevation is common, and high maximum temperature during the course of SARS-CoV-2 infection was a significant harbinger of poor outcomes. In fact, one in three patients reaching a maximum BT above 39.5 °C died. This was approximately a 5-fold increase in mortality rate as compared to patients whose temperature never broke 37 °C. In contrast, almost half of the patients initially presenting with low BT (< 35.5 °C) died. Our results, therefore, suggest that poor BT control during the COVID 19 disease course is a marker of poor prognosis and BT can be used as an easily obtained prognostic indicator.

It remains unknown if controlling the high temperature in severely ill COVID-19 patients would alleviate inflammatory response and improve their outcome. Future studies are necessary to address this question. We acknowledge the limitations of our study including unknown methods of temperature measurement, lack of follow-up of temperature in patients without hospital admission, and that the data is not adjusted for potential confounding factors. Nevertheless, a clear trend in increased mortality among the patients with poor temperature control highlights the usefulness of this non-invasively and easily obtained parameter for evaluating patients’ prognoses.

Availability of data and materials

The datasets generated and/or analyzed during the current study are not publicly available due to institutional policy but are available from the corresponding author on reasonable request.



Body temperature


  1. Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395(10223):497–506.

    Article  CAS  Google Scholar 

  2. Li X, Xu S, Yu M, et al. Risk factors for severity and mortality in adult COVID-19 inpatients in Wuhan. J Allergy Clin Immunol. 2020;S0091-6749(20):30495–4.

  3. Cunningham AC, Goh HP, Koh D. Treatment of COVID-19: old tricks for new challenges. Crit Care. 2020;24(1):91.

    Article  Google Scholar 

Download references




This work was supported by NIH R01 HL139963 (KI) and AHA-SDG 17SDG33410873 (KI).

Author information

Authors and Affiliations



ST, KN, and KI conceived and designed the study. ST, SM, and KI analyzed and interpreted the data. ST and KI drafted the manuscript. All authors revised the manuscript. All authors approved the final version of the manuscript and agreed to authorship contributions.

Corresponding author

Correspondence to Kiyotake Ishikawa.

Ethics declarations

Ethics approval and consent to participate

The IRB at the Icahn School of Medicine at Mount Sinai reviewed the data collection protocol and deemed scientific publication of the de-identified patient information exempt from the IRB review.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tharakan, S., Nomoto, K., Miyashita, S. et al. Body temperature correlates with mortality in COVID-19 patients. Crit Care 24, 298 (2020).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: