Temperature · desk opened AUG 1 2026 · revision 3 Reviewed OCT 15 2026

Temperature: What Holds Up and What Doesn't

Skin temperature shifts before you feel ill, and the evidence there is stronger than for most wearable claims. What it catches, and how early it catches it.

3 questions rated against 38 screened studies. Each rating is the evidence on that one question, not an average of the desk.

temperature hub →

Where the evidence stands · 3 questions rated the number beside each is how many studies sit behind it

Established 1 question

Does wearable temperature detect ovulation?18

Emerging 1 question

Can a wearable spot an infection before you feel it?3

Uncertain 1 question

Do consumer/research wearable temperature sensors agree with gold-standard core or reference temperature measurements?18

Do consumer/research wearable temperature sensors agree with gold-standard core or reference temperature measurements?

Rated proposition Wearable temperature sensors produce measurements that agree closely with reference-standard thermometry.

KnowYourPrime evidence rating Uncertain Evidence is conflicting, inconsistent, or difficult to interpret.

What the studies found Wearable skin/peripheral temperature sensors measure temperature-related physiological signals with accuracy sufficient to be meaningful for consumer use cases.

Anchor-grade evidence affirms the core relationship.
Multiple supporting studies are consistent with the core relationship.
An anchor study is present but its own reported finding does not cleanly affirm this claim, so it does not count toward the Established threshold.
A clean anchor supports this claim, but an unresolved conflicting study contradicts it on the core relationship, so the evidence is treated as in genuine dispute.

Used in 1 article

Can Your Wearable's Temperature Sensor Actually Catch Ovulation or Illness Before You Feel It?3 shared studies

18 studies scored · 3 anchor · 14 supporting · 1 conflicting · Evidence last evaluated Oct 15, 2026

Does wearable temperature detect ovulation?

Rated proposition Wearable skin temperature detects ovulation.

KnowYourPrime evidence rating Established Strong, consistent evidence supports the claim.

What the studies found Wrist and ring skin temperature tracks the shift that marks ovulation, closely enough to be used for fertility awareness. Accuracy depends on the sensor and the site.

Anchor-grade evidence affirms the core relationship.
Multiple supporting studies are consistent with the core relationship.

What would change this rating

A new core-hitting conflicting study, a retraction of an anchor, or a failed replication would lower this rating.

Used in 2 articles

Can Your Wearable's Temperature Sensor Actually Catch Ovulation or Illness Before You Feel It?5 shared studies
Does Wearable Temperature Tracking Actually Detect Ovulation?2 shared studies

18 studies scored · 4 anchor · 14 supporting · Evidence last evaluated Oct 15, 2026

Can a wearable spot an infection before you feel it?

Rated proposition Wearable skin temperature detects the onset of infection.

KnowYourPrime evidence rating Emerging Evidence currently favors the claim, but more confirmation is needed.

What the studies found Wrist temperature flagged infection at 80% sensitivity in a hospital pilot, and adding continuous temperature raised a COVID detection algorithm's accuracy by about 5 percent. Temperature alone has not been tested at scale.

Anchor-grade evidence affirms the core relationship.
An anchor study is present but its own reported finding does not cleanly affirm this claim, so it does not count toward the Established threshold.
The claim rests on a single anchor whose finding affirms it; a second independent affirming anchor is needed to reach Established.

Used in 1 article

Can Your Wearable's Temperature Sensor Actually Catch Ovulation or Illness Before You Feel It?1 shared study

3 studies scored · 2 anchor · 1 supporting · Evidence last evaluated Oct 15, 2026

MAINTAINED BY The KnowYourPrime Research Desk · reviewed against new evidence on a rolling basis

Evidence on: Wearable temperature sensors produce measurements that agree closely with reference-standard thermometry.

18 scored

Anchor Studies3

Accuracy of next-generation wireless skin temperature sensors during exercise-heat stress.

Journal

Experimental physiology · 2026

PMID

42261995

Citations

Study type

Primary study

Sample size

10 women

humansfemale

Core Temperature Estimation Using Wearable Earbud-Type Thermometer and Machine Learning During Light-Intensity Cycling Under Varying Indoor Ambient Temperatures.

Journal

Scandinavian journal of medicine & science in sports · 2026

PMID

42257542

Citations

Study type

Primary study

humansthermometers

Performance comparison of a wired zero-heat-flux sensor and wireless thermistor patch with esophageal probe for core temperature monitoring.

Journal

Scientific reports · 2026

PMID

42049813

Citations

Study type

Comparative study

Sample size

24 subjects

humansfemale

Supporting Studies14

Wearable physiological monitoring for human thermal-work strain optimization.

Journal

Journal of applied physiology (Bethesda, Md. : 1985) · 2019

PMID

28798200

RCR

4.5

Citations

Study type

Review

body temperatureheat stress disorders

Wearable Personal Core Body Temperature Measurement Considering Individual Differences and Dynamic Tissue Blood Perfusion.

Journal

IEEE journal of biomedical and health informatics · 2022

PMID

34727042

RCR

2.1

Citations

Study type

Primary study

body temperaturehumans

Thermoregulation and Heat Stroke Prevention in Older Adults: Advances in Emerging Technologies and Interventions.

Journal

Sensors (Basel, Switzerland) · 2025

PMID

41305264

Citations

Study type

Systematic review

humansbody temperature regulation

Noninvasive Continuous Temperature Monitoring in Oncology and Future Directions.

Journal

Clinical journal of oncology nursing · 2025

PMID

40401828

Citations

Study type

Review

humansmonitoring, physiologic

A Comprehensive Review of Non-Invasive Core Body Temperature Measurement Techniques.

Journal

Sensors (Basel, Switzerland) · 2026

PMID

41682487

RCR

4.8

Citations

Study type

Review

humansbody temperature

Limited efficacy of low-volume ice slurry ingestion on physiological heat strain in Japanese outdoor workers during summer.

Journal

Annals of human biology · 2026

PMID

42530119

Citations

Study type

Primary study

humansjapan

A Wearable System for Remote Wrist Skin Temperature Monitoring to Assess Skin Thermal Response to Extreme Cold: A Case Study.

Journal

Sensors (Basel, Switzerland) · 2026

PMID

42198043

Citations

Study type

Primary study

humansskin temperature

Multimodal Fusion of Environmental and Physiological Data for Real-World Personalised Comfort Modelling.

Journal

Sensors (Basel, Switzerland) · 2026

PMID

42197750

Citations

Study type

Primary study

humansenvironment

Evaluation of Exertional Sweat Loss Estimates in Wearable Technology.

Journal

Sports health · 2026

PMID

41320899

Citations

Study type

Primary study

Sample size

111 participants

humanswearable electronic devices

Minimally invasive prediction of blood lactate during incremental exercise via heart rate, core body temperature, and sweat-derived indices.

Journal

Scientific reports · 2026

PMID

41946811

Citations

Study type

Primary study

humansheart rate

Use of continuous temperature data from wearable devices for fever or infection management in acute hospital settings: a scoping review protocol.

Journal

BMJ open · 2025

PMID

41469073

Citations

Study type

Primary study

humansscoping reviews as topic

Temperature measurements of a wearable and wireless axillary sensor iThermonitor but not a bladder probe represents the core temperature during laparoscopic rectal surgery.

Journal

Journal of clinical monitoring and computing · 2023

PMID

35788943

RCR

1.4

Citations

Study type

Primary study

adulthumans

Smart Patch for Skin Temperature: Preliminary Study to Evaluate Psychometrics and Feasibility.

Journal

Sensors (Basel, Switzerland) · 2021

PMID

33800920

RCR

0.6

Citations

Study type

Primary study

Sample size

35 participants

adultbody temperature

An Innovative Wearable Device For Monitoring Continuous Body Surface Temperature (HEARThermo): Instrument Validation Study.

Journal

JMIR mHealth and uHealth · 2021

PMID

33565990

RCR

0.4

Citations

Study type

Primary study

adolescentadult

Conflicting Studies1

Performance of a wearable CORE sensor for nocturnal core temperature monitoring during sleep.

Journal

Journal of thermal biology · 2026

PMID

42086019

Citations

Study type

Primary study

Bears on

Core claim

humansfemale

Evidence on: Wearable skin temperature detects ovulation.

18 scored

Anchor Studies4

Modern fertility awareness methods: wrist wearables capture the changes in temperature associated with the menstrual cycle.

Journal

Bioscience reports · 2019

PMID

29175999

RCR

4.3

Citations

Study type

Primary study

adultbody temperature

The Accuracy of Wrist Skin Temperature in Detecting Ovulation Compared to Basal Body Temperature: Prospective Comparative Diagnostic Accuracy Study.

Journal

Journal of medical Internet research · 2021

PMID

34100763

RCR

3.7

Citations

Study type

Primary study

Sample size

n = 193

body temperaturefemale

Evaluation of the accuracy of wrist skin temperature measured using an infrared sensor for prediction ovulation date.

Journal

Biosensors & bioelectronics · 2026

PMID

42143892

Citations

Study type

Primary study

Sample size

106 women

humansfemale

Accuracy of an Overnight Axillary-Temperature Sensor for Ovulation Detection: Validation in 194 Cycles.

Journal

Sensors (Basel, Switzerland) · 2025

PMID

41157380

Citations

Study type

Primary study

Sample size

125 women

femalehumans

Supporting Studies14

Using Wearable Skin Temperature Data to Advance Tracking and Characterization of the Menstrual Cycle in a Real-World Setting.

Journal

Journal of biological rhythms · 2024

PMID

38767963

RCR

3.7

Citations

Study type

Primary study

humansfemale

Menstrual Cycle Variations in Wearable-Detected Finger Temperature and Heart Rate, But Not in Sleep Metrics, in Young and Midlife Individuals.

Journal

Journal of biological rhythms · 2024

PMID

39108015

RCR

2.6

Citations

Study type

Primary study

Sample size

96 participants

humansfemale

The use of wearable devices for predicting biphasic basal body temperature to estimate the date of ovulation in women.

Journal

Journal of thermal biology · 2022

PMID

36031211

RCR

1.9

Citations

Study type

Review

body temperaturefemale

Detection and Prediction of Ovulation From Body Temperature Measured by an In-Ear Wearable Thermometer.

Journal

IEEE transactions on bio-medical engineering · 2020

PMID

31095472

RCR

1.7

Citations

Study type

Primary study

adultalgorithms

Deep learning model using continuous skin temperature data predicts labor onset.

Journal

BMC pregnancy and childbirth · 2024

PMID

39587525

RCR

1.0

Citations

Study type

Primary study

Sample size

n = 54

humansfemale

Monitoring skin temperature at the wrist in hospitalised patients may assist in the detection of infection.

Journal

Internal medicine journal · 2021

PMID

31908128

RCR

1.0

Citations

Study type

Primary study

Sample size

n = 60

adultcross-sectional studies

Continuous body temperature as a window into adolescent development.

Journal

Developmental cognitive neuroscience · 2023

PMID

36821877

RCR

0.7

Citations

Study type

Review

femaleadolescent

State-dependent skin temperature increase during manic episodes of bipolar disorder.

Journal

Journal of affective disorders · 2025

PMID

40499838

Citations

Study type

Primary study

humansbipolar disorder

Wrist temperature as a sleep marker in actigraphy.

Journal

Chronobiology international · 2026

PMID

41324514

Citations

Study type

Primary study

humansactigraphy

Effectiveness of menstruation and fertility tracking technology in childbearing women: a scoping review.

Journal

Revista da Escola de Enfermagem da U S P · 2025

PMID

41085255

Citations

Study type

Review

Sample size

26,044 participants

humansfemale

Measuring Skin Temperature as an Indicator for Cognitive Flow Using a Wrist-worn Wearable.

Journal

Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference · 2025

PMID

40039242

RCR

0.0

Citations

Study type

Primary study

humanswearable electronic devices

Distal skin temperature stabilization is tightly coupled with sleep onset across structured and free-living conditions.

Journal

Sleep medicine · 2026

PMID

42330816

Citations

Study type

Primary study

humansfemale

Age-related patterns in distal skin temperature during naps.

Journal

Sleep · 2026

PMID

41841798

Citations

Study type

Primary study

Sample size

027 individuals

humansskin temperature

Physiological Effects of Far-Infrared-Emitting Garments on Sleep, Thermoregulation, and Autonomic Function Assessed Using Wearable Sensors.

Journal

Sensors (Basel, Switzerland) · 2026

PMID

41600346

Citations

Study type

Randomized controlled trial

humansmale

Evidence on: Wearable skin temperature detects the onset of infection.

3 scored

Anchor Studies2

Monitoring skin temperature at the wrist in hospitalised patients may assist in the detection of infection.

Journal

Internal medicine journal · 2021

PMID

31908128

RCR

1.0

Citations

Study type

Primary study

Sample size

n = 60

adultcross-sectional studies

Detection of COVID-19 using multimodal data from a wearable device: results from the first TemPredict Study.

Journal

Scientific reports · 2022

PMID

35236896

RCR

4.5

Citations

Study type

Primary study

Sample size

63,153 participants

adolescentadult

Supporting Studies1

Real-time infection prediction with wearable physiological monitoring and AI to aid military workforce readiness during COVID-19.

Journal

Scientific reports · 2022

PMID

35260671

RCR

3.6

Citations

Study type

Primary study

algorithmsarea under curve

01 Research Log

AUG 1 2026

Evaluation of the accuracy of wrist skin temperature measured using an infrared sensor for prediction ovulation date. (Biosensors & bioelectronics 2026) entered as anchor on the cycle_illness_detection claim.

Continuous body temperature as a window into adolescent development. (Developmental cognitive neuroscience 2023) entered as supporting on the cycle_illness_detection claim.

State-dependent skin temperature increase during manic episodes of bipolar disorder. (Journal of affective disorders 2025) entered as supporting on the cycle_illness_detection claim.

The use of wearable devices for predicting biphasic basal body temperature to estimate the date of ovulation in women. (Journal of thermal biology 2022) entered as supporting on the cycle_illness_detection claim.

Distal skin temperature stabilization is tightly coupled with sleep onset across structured and free-living conditions. (Sleep medicine 2026) entered as anchor on the cycle_illness_detection claim.

Detection of COVID-19 using multimodal data from a wearable device: results from the first TemPredict Study. (Scientific reports 2022) entered as anchor on the cycle_illness_detection claim.

Modern fertility awareness methods: wrist wearables capture the changes in temperature associated with the menstrual cycle. (Bioscience reports 2019) entered as anchor on the cycle_illness_detection claim.

Wrist temperature as a sleep marker in actigraphy. (Chronobiology international 2026) entered as supporting on the cycle_illness_detection claim.

Age-related patterns in distal skin temperature during naps. (Sleep 2026) entered as supporting on the cycle_illness_detection claim.

Measuring Skin Temperature as an Indicator for Cognitive Flow Using a Wrist-worn Wearable. (Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2025) entered as supporting on the cycle_illness_detection claim.

Detection and Prediction of Ovulation From Body Temperature Measured by an In-Ear Wearable Thermometer. (IEEE transactions on bio-medical engineering 2020) entered as supporting on the cycle_illness_detection claim.

Monitoring skin temperature at the wrist in hospitalised patients may assist in the detection of infection. (Internal medicine journal 2021) entered as supporting on the cycle_illness_detection claim.

Using Wearable Skin Temperature Data to Advance Tracking and Characterization of the Menstrual Cycle in a Real-World Setting. (Journal of biological rhythms 2024) entered as supporting on the cycle_illness_detection claim.

Menstrual Cycle Variations in Wearable-Detected Finger Temperature and Heart Rate, But Not in Sleep Metrics, in Young and Midlife Individuals. (Journal of biological rhythms 2024) entered as supporting on the cycle_illness_detection claim.

Deep learning model using continuous skin temperature data predicts labor onset. (BMC pregnancy and childbirth 2024) entered as supporting on the cycle_illness_detection claim.

Effectiveness of menstruation and fertility tracking technology in childbearing women: a scoping review. (Revista da Escola de Enfermagem da U S P 2025) entered as supporting on the cycle_illness_detection claim.

The Accuracy of Wrist Skin Temperature in Detecting Ovulation Compared to Basal Body Temperature: Prospective Comparative Diagnostic Accuracy Study. (Journal of medical Internet research 2021) entered as anchor on the cycle_illness_detection claim.

Accuracy of an Overnight Axillary-Temperature Sensor for Ovulation Detection: Validation in 194 Cycles. (Sensors (Basel, Switzerland) 2025) entered as anchor on the cycle_illness_detection claim.

Physiological Effects of Far-Infrared-Emitting Garments on Sleep, Thermoregulation, and Autonomic Function Assessed Using Wearable Sensors. (Sensors (Basel, Switzerland) 2026) entered as supporting on the cycle_illness_detection claim.

Performance of a wearable CORE sensor for nocturnal core temperature monitoring during sleep. (Journal of thermal biology 2026) entered as anchor on the measurement_validity claim.

Minimally invasive prediction of blood lactate during incremental exercise via heart rate, core body temperature, and sweat-derived indices. (Scientific reports 2026) entered as supporting on the measurement_validity claim.

Performance comparison of a wired zero-heat-flux sensor and wireless thermistor patch with esophageal probe for core temperature monitoring. (Scientific reports 2026) entered as anchor on the measurement_validity claim.

Limited efficacy of low-volume ice slurry ingestion on physiological heat strain in Japanese outdoor workers during summer. (Annals of human biology 2026) entered as supporting on the measurement_validity claim.

Wearable Personal Core Body Temperature Measurement Considering Individual Differences and Dynamic Tissue Blood Perfusion. (IEEE journal of biomedical and health informatics 2022) entered as supporting on the measurement_validity claim.

Core Temperature Estimation Using Wearable Earbud-Type Thermometer and Machine Learning During Light-Intensity Cycling Under Varying Indoor Ambient Temperatures. (Scandinavian journal of medicine & science in sports 2026) entered as anchor on the measurement_validity claim.

Accuracy of next-generation wireless skin temperature sensors during exercise-heat stress. (Experimental physiology 2026) entered as anchor on the measurement_validity claim.

Use of continuous temperature data from wearable devices for fever or infection management in acute hospital settings: a scoping review protocol. (BMJ open 2025) entered as supporting on the measurement_validity claim.

Wearable physiological monitoring for human thermal-work strain optimization. (Journal of applied physiology (Bethesda, Md. : 1985) 2019) entered as supporting on the measurement_validity claim.

Evaluation of Exertional Sweat Loss Estimates in Wearable Technology. (Sports health 2026) entered as supporting on the measurement_validity claim.

Noninvasive Continuous Temperature Monitoring in Oncology and Future Directions. (Clinical journal of oncology nursing 2025) entered as supporting on the measurement_validity claim.

Thermoregulation and Heat Stroke Prevention in Older Adults: Advances in Emerging Technologies and Interventions. (Sensors (Basel, Switzerland) 2025) entered as supporting on the measurement_validity claim.

A Comprehensive Review of Non-Invasive Core Body Temperature Measurement Techniques. (Sensors (Basel, Switzerland) 2026) entered as supporting on the measurement_validity claim.

Multimodal Fusion of Environmental and Physiological Data for Real-World Personalised Comfort Modelling. (Sensors (Basel, Switzerland) 2026) entered as supporting on the measurement_validity claim.

A Wearable System for Remote Wrist Skin Temperature Monitoring to Assess Skin Thermal Response to Extreme Cold: A Case Study. (Sensors (Basel, Switzerland) 2026) entered as supporting on the measurement_validity claim.

SEP 4 2026

Temperature measurements of a wearable and wireless axillary sensor iThermonitor but not a bladder probe represents the core temperature during laparoscopic rectal surgery. (Journal of clinical monitoring and computing 2023) entered as supporting on the measurement_validity claim.

Smart Patch for Skin Temperature: Preliminary Study to Evaluate Psychometrics and Feasibility. (Sensors (Basel, Switzerland) 2021) entered as supporting on the measurement_validity claim.

SEP 30 2026

Detection of COVID-19 using multimodal data from a wearable device: results from the first TemPredict Study. (Scientific reports 2022) entered as anchor on the illness_detection claim.

Real-time infection prediction with wearable physiological monitoring and AI to aid military workforce readiness during COVID-19. (Scientific reports 2022) entered as supporting on the illness_detection claim.

Monitoring skin temperature at the wrist in hospitalised patients may assist in the detection of infection. (Internal medicine journal 2021) entered as anchor on the illness_detection claim.

OCT 2 2026

Performance of a wearable CORE sensor for nocturnal core temperature monitoring during sleep. (Journal of thermal biology 2026) entered as conflicting on the measurement_validity claim.

OCT 2 2026

Performance of a wearable CORE sensor for nocturnal core temperature monitoring during sleep. (Journal of thermal biology 2026) entered as a conflicting study on the measurement_validity claim, bearing on the core claim.

It caps the rating until reconciled.

OCT 2 2026

OCT 15 2026

An Innovative Wearable Device For Monitoring Continuous Body Surface Temperature (HEARThermo): Instrument Validation Study. (JMIR mHealth and uHealth 2021) entered as supporting on the measurement_validity claim.

02 Revision Log

OCT 2 2026

measurement_validity: Established → Uncertain

Moved to Uncertain by rule from the current evidence for: Wearable temperature sensors produce measurements that agree closely with reference-standard thermometry..

SEP 30 2026

illness_detection: opened at Emerging

Opened at Emerging by rule from the current evidence for: Wearable skin temperature detects the onset of infection..

AUG 1 2026

cycle_illness_detection: opened at Established

Opened at Established by rule from the current evidence for: Wearable-measured temperature patterns track physiologically meaningful state changes such as ovulation or illness onset..

AUG 1 2026

measurement_validity: opened at Established

Opened at Established by rule from the current evidence for: Wearable temperature sensors produce measurements that agree closely with reference-standard thermometry..

This page interprets published research. It is not medical advice. The KnowYourPrime Research Desk rates the evidence supporting a claim, not the claim itself. It does not diagnose or treat. Talk to your own doctor about your health.