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Postmortem interval from temperature (Henssge)

Estimates the early post-mortem interval from a rectal temperature measurement using the double-exponential cooling model underlying Henssge’s nomogram.

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Method · Limits of application

Henssge: technical equation of Otatsume et al. 2024 (up to 23 °C: 5/4 and 1/4; above 23 °C: 10/9 and 1/9); numerical bisection; the 1988 original was not read in full

The Henssge estimate depends on the cooling model and a rectal measurement, with environmental conditions and correction factors defined in the version. It is not an exact time of death. The numerical solution and uncertainty must match the case conditions and source; the original abstract does not allow all these criteria to be confirmed. This variant declares the technical equation of Otatsume and colleagues, 2024, whose equations 1–4 were read on page 2 of the article: A = 5/4 for ambient temperature up to 23 °C and A = 10/9 above 23 °C. The coefficient 10/9 is used as a fraction, without replacing it with 1.11. The B term, the factor applied to weight, the input limits and the numerical solution remain those of this interface. The 2019 publication prints 1.11 and 0.11, a different ambient-temperature boundary and a different placement of the correction factor; that edition is retained as a comparison, not as proof of full equivalence. The 1988 original was not read in full. This check does not approve an individual time of death, selection of correction factors, uncertainty, the confidence interval or forensic use.

Conditions of use

Check the population, units, inclusion and exclusion criteria, and version in the original source. A result alone does not establish a diagnosis, discharge decision or prescription.

Documented parameters

Deep rectal temperature · °C
Ambient temperature (local mean) · °C
Body weight · kg
Weight correction factor (1.0 = naked, dry body in still air)

4/4 reference cases checked. Numerical tests are not clinical validation.

Sources and documentation

Documented formula

Transcribed from the source or a recorded revision; this is not a clinical recommendation.

Standardized temperature: Q = (T_rectal − T_ambient) / (37.2 − T_ambient).

Ambient temperature up to 23 °C: Q = 1.25 × e^Bt − 0.25 × e^5Bt. Ambient temperature above 23 °C: Q = (10/9) × e^Bt − (1/9) × e^10Bt.

B = −1.2815 × (factor × weight)^−0.625 + 0.0284. Time t (hours) is found by numerically solving the equation, as in the nomogram.

References

Identifier: intervalo-post-mortem-henssge

Original clinical content: Brazilian Portuguese.

Method version

Henssge: technical equation of Otatsume et al. 2024 (up to 23 °C: 5/4 and 1/4; above 23 °C: 10/9 and 1/9); numerical bisection; the 1988 original was not read in full

intervalo-post-mortem-henssge@native-2026-10-05+51aa703c8009

Source for the active edition

The bibliographic edition identifies the source. By itself, it proves neither full conformity of the formula nor clinical approval.

Synthetic cases checked (4)

Synthetic cases for checking the implementation, with no patient data.

Case 1

reference-001

Inputs

Deep rectal temperature: 31.41 °C
Ambient temperature (local mean): 20 °C
Body weight: 70 kg
Weight correction factor (1.0 = naked, dry body in still air): 1

{
  "tr": 31.41,
  "ta": 20,
  "peso": 70,
  "fc": 1
}

Expected result

{
  "t": 10,
  "B": -0.06166
}

Actual result

{
  "t": 9.99718202958405,
  "B": -0.061660081472802435,
  "q": 0.6633720930232557
}

Case 2

reference-002

Inputs

Deep rectal temperature: 34.72 °C
Ambient temperature (local mean): 25 °C
Body weight: 80 kg

{
  "tr": 34.72,
  "ta": 25,
  "peso": 80
}

Expected result

{
  "t": 6,
  "B": -0.05445
}

Actual result

{
  "t": 6.01190779100004,
  "B": -0.05444901866913413,
  "q": 0.7967213114754096
}

Case 3

reference-003

Inputs

Deep rectal temperature: 38 °C
Ambient temperature (local mean): 20 °C
Body weight: 70 kg

{
  "tr": 38,
  "ta": 20,
  "peso": 70
}

Expected result

{
  "error": true
}

Case 4

reference-004

Inputs

Deep rectal temperature: 20 °C
Ambient temperature (local mean): 20 °C
Body weight: 70 kg

{
  "tr": 20,
  "ta": 20,
  "peso": 70
}

Expected result

{
  "error": true
}

Code and reproducibility

This tool’s code on GitHub

Download code and tests

Sources, version and reproduction instructions

README

Local installation

Code license: Apache-2.0

Guidelines and conditions

This repository’s license applies to the code. Third-party instruments, questionnaires, data and models remain subject to their owners’ conditions.

The code tests are technical checks. Clinical approval and professional translation review are recorded separately.

Relationship with cancer research

General context — relationship to be defined

A resource for general clinical contexts. This edition does not assign a specific oncological relationship; selecting it for a study requires a justified question, population and purpose.