1712: "The Hidden Heat Sensor in a Dog's Nose"
Interesting Things with JC #1712: "The Hidden Heat Sensor in a Dog's Nose"
Dogs repeatedly choose one of two identical targets after researchers control visual and scent cues. The targets sit five feet away and appear the same, but one difference keeps producing the same choice.
Curriculum - Episode Anchor
Episode Title: The Hidden Heat Sensor in a Dog's Nose
Episode Number: 1712
Host: JC
Audience: Grades 9–12, Introductory College, Homeschool, Lifelong Learners
Subject Area: Biology, Animal Sensory Systems, Neuroscience
Lesson Overview
Learning Objectives:
Explain the function of the canine rhinarium and distinguish thermal detection from olfaction.
Analyze behavioral and functional MRI evidence used to investigate thermal sensing in dogs.
Evaluate the difference between a demonstrated scientific finding and a hypothesis requiring further testing.
Apply evidence-based reasoning to explain how multiple sensory systems may support animal behavior.
Essential Question: How can scientists use behavioral and neurological evidence to identify a previously unrecognized sensory ability?
Success Criteria: Students can accurately define rhinarium and thermal radiation, describe both parts of the 2020 investigation, distinguish evidence from hypothesis, and construct a claim supported by specific evidence from the episode.
Student Relevance Statement: Familiar animals can possess biological abilities that remain scientifically understudied. This lesson shows how careful observation, controlled testing, and brain imaging can change scientific understanding.
Real-World Connection: Behavioral experiments and neuroimaging are used to investigate how animals and humans process sensory information. The same habits of controlling variables, comparing evidence, and limiting conclusions are valuable in science, medicine, technology, and research.
Workforce Reality: Research involving animal behavior and neuroscience requires disciplined observation, accurate data collection, ethical procedures, technical training, collaboration, and professional judgment. Interesting findings must be supported by reproducible evidence rather than assumption.
Key Vocabulary
Rhinarium(rye-NAIR-ee-um): The smooth, hairless external surface at the tip of a dog's nose.
Thermal radiation(THER-muhl ray-dee-AY-shun): Energy emitted by an object because of its temperature.
Infrared(in-fruh-RED): A region of electromagnetic radiation associated with heat and wavelengths longer than visible red light.
Olfaction(ol-FAK-shun): The biological sense of smell.
Sensory receptor(SEN-suh-ree ree-SEP-ter): A biological structure that responds to a specific type of stimulus.
Functional MRI(FUNK-shuh-nuhl em-ar-EYE): A brain-imaging method used to detect changes associated with neural activity.
Somatosensory association cortex(soh-MAT-oh-SEN-suh-ree uh-soh-see-AY-shun KOR-teks): A brain region involved in processing and integrating sensory information related to the body.
Stimulus(STIM-yuh-lus): A detectable change or signal capable of producing a biological response.
Variable(VAIR-ee-uh-buhl): A factor that can change or be controlled during an investigation.
Narrative Core
Open: Dogs are widely recognized for exceptional smell, but the tip of the canine nose may detect more than airborne chemicals.
Info: The rhinarium appears capable of detecting weak thermal radiation emitted by warm objects.
Details: Researchers used a controlled behavioral task in which dogs distinguished a warm target from a room-temperature target. Functional MRI observations in thirteen awake dogs also identified increased activity in the left somatosensory association cortex during exposure to weak thermal stimuli.
Reflection: The findings demonstrate how separate forms of evidence can support a scientific explanation. Behavioral performance showed that dogs could respond to the heat difference, while brain imaging provided evidence that sensory processing occurred in a region associated with somatosensory information. Possible advantages for locating warm animals or helping newborn puppies orient toward maternal warmth remain areas for further investigation.
Closing: These are interesting things, with JC.
Close-up photograph of a golden-colored dog resting its head on a wooden surface, with its textured black nose prominently centered in the foreground. White text above reads, “The Hidden Heat Sensor in a Dog’s Nose,” with “Interesting Things with JC #1712” at the top.
Transcript
Interesting Things with JC #1712:
"The Hidden Heat Sensor in a Dog's Nose"
A dog's nose is famous for its sense of smell, with up to 300 million scent receptors compared to about six million in humans. But scientists have discovered the tip of that nose may have another remarkable ability.
The smooth, hairless tip, called the rhinarium (rye-NAIR-ee-um), appears to detect weak thermal radiation—the infrared heat naturally emitted by warm objects.
In a 2020 study, researchers trained dogs to choose between two identical targets about five feet, or 1.6 meters, away. One was warmed to about 88 degrees Fahrenheit, or 31 degrees Celsius, roughly the surface temperature of a small mammal. The other stayed at room temperature. Even with visual and scent cues controlled, the dogs consistently chose the warmer target.
Functional MRI scans of thirteen awake dogs supported the findings. When the animals detected weak heat signals, researchers saw activity in the left somatosensory association cortex, indicating the rhinarium was processing thermal information separately from smell.
Dogs don't see heat the way pit vipers do. Instead, this appears to be another sensory tool working alongside smell and hearing. A rabbit hidden in tall grass or a deer standing motionless still gives off heat, and that subtle signal could help a predator pinpoint its location.
Researchers also believe the ability may benefit newborn puppies. Born blind and deaf, they depend on warmth during their first weeks, and detecting their mother's body heat could help them find her to nurse, although that idea has not yet been directly tested.
For generations, a dog's cool, wet nose was simply considered part of being a dog. It now appears that same nose may be detecting a form of energy that humans can't sense at all.
These are interesting things, with JC.
Student Worksheet
Comprehension Questions:
What is the rhinarium?
What form of energy does the canine rhinarium appear to detect?
How were the two targets in the behavioral experiment different?
What did the dogs consistently choose during the experiment?
Which brain region showed increased activity during exposure to weak heat signals?
Analysis Questions:
Why was it important for researchers to control visual and scent cues?
Explain how the behavioral experiment and functional MRI evidence support each other.
What is the difference between saying dogs detect thermal radiation and saying dogs "see heat"?
Identify one conclusion supported by direct evidence and one proposed biological benefit that requires further testing.
Reflection Prompt: Describe a familiar animal trait that people may take for granted. What controlled evidence would scientists need to determine whether that trait performs an additional sensory or biological function?
Difficulty Scaling: Level 1 students should answer comprehension questions using complete sentences. Level 2 students should complete all questions and cite episode details in each analysis response. Level 3 students should complete all tasks and construct a claim-evidence-reasoning response comparing demonstrated thermal detection with the proposed newborn-puppy hypothesis.
Student Output: Submit five comprehension responses, four analysis responses, and one reflection paragraph of 100–150 words. Level 3 work should also include a 150–200-word claim-evidence-reasoning response.
Academic Integrity Guidance: Use the episode and class materials as evidence. Write explanations in your own words, identify specific observations or experimental details, and do not invent data that the researchers did not report.
Teacher Guide
Quick Start: Begin with the podcast audio before providing explanations. Ask students to listen for the body structure being studied, the signal being detected, and two forms of scientific evidence.
Pacing Guide: 0–2 minutes: introduce the listening purpose without explaining the finding. 2–5 minutes: play the podcast. 5–10 minutes: students record evidence independently. 10–20 minutes: review vocabulary and reconstruct the experiment. 20–35 minutes: complete worksheet analysis. 35–45 minutes: discussion and formative checks. 45–55 minutes: quiz or open-ended assessment. 55–60 minutes: exit ticket.
Bell Ringer: Write one sensory ability commonly associated with dogs. Then identify one variable a scientist would need to control when testing that ability.
Audio Guidance: Play the episode first. Students should listen for three categories: structure, stimulus, and evidence. Encourage note-taking with single words or short phrases during the first listen.
Audio Fallback: If audio is unavailable, the teacher should read the transcript aloud without stopping for explanation. Students should follow the same structure-stimulus-evidence listening task. A silent transcript reading may be used when oral delivery is not possible.
Time on Task: Standard lesson length is 55–60 minutes. The core audio, evidence analysis, and exit ticket can be completed in approximately 35 minutes.
Materials:
Podcast audio or transcript
Student Worksheet
Writing materials or digital response platform
Optional diagram of the canine nose
Optional display for experiment reconstruction
Vocabulary Strategy: Preteach only thermal radiation and variable before listening if needed. Introduce rhinarium after students hear the term in context. Ask students to use rhinarium, stimulus, and thermal radiation accurately during discussion.
Misconceptions:
Dogs are not described as producing a thermal image comparable to human vision.
Thermal detection is not the same process as smell.
Infrared radiation does not require an object to be visibly glowing.
Brain activity alone does not explain every behavioral purpose of a sensory ability.
The proposed benefit to newborn puppies has not been directly demonstrated by the described study.
Discussion Prompts:
Which part of the study provides behavioral evidence?
Which part provides neurological evidence?
Why are identical targets important to the experimental design?
What language in the episode signals scientific uncertainty?
Why should researchers avoid presenting the puppy hypothesis as a proven conclusion?
Formative Checkpoints: After audio, students identify the rhinarium and thermal radiation. After vocabulary, students explain the experiment in three sentences. Before assessment, students classify statements as direct evidence, interpretation, or hypothesis.
Differentiation: Provide a three-column organizer labeled Structure, Stimulus, and Evidence for students needing support. Allow advanced students to evaluate whether the experiment demonstrates detection ability, ecological function, or both. English learners may use the vocabulary pronunciation guide and sentence frames for claim-evidence reasoning.
Assessment Differentiation: Students needing writing support may provide structured claim-evidence-reasoning responses with labeled fields. Advanced students should evaluate the limits of the evidence and propose a controlled follow-up investigation.
Time Flexibility: For a 30-minute lesson, play the audio, complete comprehension questions 1–5, discuss analysis questions 1 and 4, and use the exit ticket. For a 90-minute block, add experiment-design work and peer review.
Substitute Readiness: Play or read the episode first. Direct students to complete the worksheet independently. Review the comprehension answer key, discuss the distinction between evidence and hypothesis, administer the quiz, and collect the exit ticket.
Engagement Strategy: Ask students to reconstruct the experiment using a simple diagram of two visually identical targets. Before revealing the outcome, have students identify possible confounding variables and predict what evidence would support thermal detection.
Extensions: Design a follow-up experiment testing distance limits of thermal detection. Compare thermal sensing across animal species. Research how scientists use functional MRI to investigate sensory processing.
Cross-Curricular Connections: Physics connects through infrared radiation and energy transfer. Psychology and neuroscience connect through sensory processing and brain activity. English language arts connects through evidence evaluation and precise claims. Career education connects through experimental discipline and technical communication.
SEL Connection: Students practice intellectual humility by separating what is known from what remains uncertain. Collaborative discussion requires listening, revising interpretations, and responding to evidence.
Skill Value Emphasis: The lesson develops analytical thinking, evidence evaluation, controlled reasoning, communication, and professional judgment. Students practice resisting unsupported conclusions even when an explanation appears plausible.
Answer Key:
Comprehension: 1. The rhinarium is the smooth, hairless tip of a dog's nose. 2. It appears to detect weak thermal radiation or infrared heat from warm objects. 3. One target was warmed to approximately 88°F or 31°C while the other remained at room temperature. 4. The dogs consistently selected the warmer target. 5. The left somatosensory association cortex showed increased activity.
Analysis: 1. Controlling visual and scent cues reduced alternative explanations for the dogs' choices. 2. The behavioral test demonstrated successful discrimination between targets, while functional MRI provided neurological evidence of sensory processing associated with weak heat stimuli. 3. Detecting thermal radiation means responding to a heat-related signal; the study does not show that dogs form a visual thermal image. 4. Direct evidence supports the ability to discriminate weak thermal stimuli. A possible role in helping newborn puppies locate maternal warmth remains a hypothesis requiring direct testing.
Reflection: Answers will vary. Strong responses identify a testable animal trait, define a measurable outcome, and describe controls that reduce alternative explanations.
Quiz
Questions:
What is the rhinarium?
A. A brain region responsible for smell
B. The smooth, hairless tip of a dog's nose
C. A receptor located in the inner ear
D. A gland that controls body temperatureWhat was the primary difference between the two experimental targets?
A. Their color
B. Their scent
C. Their temperature
D. Their distance from the dogsWhy did researchers use functional MRI?
A. To measure the dogs' body temperatures
B. To observe brain activity associated with weak heat stimuli
C. To increase the temperature of the rhinarium
D. To test the dogs' hearing rangeWhich statement is best supported by the evidence described in the episode?
A. Dogs create detailed visual images of infrared radiation.
B. Dogs use thermal detection only when hunting.
C. Dogs can distinguish weak thermal signals from a distance.
D. All newborn mammals locate their mothers through infrared detection.Which statement represents a hypothesis requiring further direct testing?
A. The rhinarium is located at the tip of the dog's nose.
B. Dogs selected the warmer experimental target.
C. Heat stimuli were associated with activity in a somatosensory brain region.
D. Thermal detection may help newborn puppies locate their mother to nurse.
Assessment
Open-Ended Questions:
Using evidence from the behavioral experiment and functional MRI observations, explain why researchers concluded that the canine rhinarium can detect weak thermal radiation. Include at least two specific pieces of evidence.
Evaluate the proposed idea that thermal detection may help newborn puppies locate their mother. Explain why the idea is biologically plausible and why it should still be described as a hypothesis.
3–2–1 Rubric:
3 — Proficient: Makes an accurate claim, uses specific evidence from the episode, and clearly explains the reasoning connecting evidence to the conclusion.
2 — Developing: Makes a generally accurate claim and includes relevant evidence but provides incomplete reasoning or limited precision.
1 — Beginning: Provides an unsupported, inaccurate, or incomplete claim with little connection to episode evidence.
Exit Ticket: In two sentences, identify one finding directly supported by the study and one question that remains open for future research.
Standards Alignment
NGSS — Science & Engineering Practices
SEP: Planning and Carrying Out Investigations — Planning and conducting investigations to collect data as evidence. Direct Connection: Students reconstruct the controlled warm-target experiment and identify visual and scent cues as variables requiring control. Measurable Skill: Students identify at least two experimental controls and explain their purpose. Justification: The worksheet and discussion require students to evaluate how controlled testing supports a sensory claim.
SEP: Analyzing and Interpreting Data — Analyzing data to provide valid and reliable evidence. Direct Connection: Students compare behavioral outcomes with functional MRI observations. Measurable Skill: Students use two different forms of evidence to support a conclusion about thermal detection. Justification: Assessment Question 1 measures the student's ability to synthesize behavioral and neurological evidence.
CCSS Reading
CCSS.ELA-LITERACY.RST.11-12.1 — Cite specific textual evidence to support analysis of science and technical texts. Direct Connection: Students use specific experimental details from the episode and transcript in analysis responses. Measurable Skill: Students cite at least two relevant details when explaining the scientific conclusion. Justification: The worksheet, quiz, and assessment require evidence-based interpretation of scientific information.
CCSS.ELA-LITERACY.RST.11-12.2 — Determine central ideas or conclusions of a text and summarize complex concepts accurately. Direct Connection: Students distinguish the central finding of thermal detection from proposed ecological functions. Measurable Skill: Students accurately summarize the study's demonstrated conclusion and one unresolved hypothesis. Justification: The exit ticket directly measures accurate separation of established findings and open questions.
CCSS Writing
CCSS.ELA-LITERACY.WHST.11-12.1 — Write arguments focused on discipline-specific content. Direct Connection: Students construct a claim-evidence-reasoning response about canine thermal detection. Measurable Skill: Students produce a defensible claim supported by relevant scientific evidence and reasoning. Justification: The Level 3 worksheet task and open-ended assessment require evidence-based scientific argumentation.
CCSS.ELA-LITERACY.WHST.11-12.9 — Draw evidence from informational texts to support analysis, reflection, and research. Direct Connection: Students use the transcript as an informational source when answering analysis and reflection tasks. Measurable Skill: Students integrate episode evidence without inventing unsupported data. Justification: Academic integrity guidance and assessment tasks explicitly require source-based reasoning.
CCSS Speaking & Listening
CCSS.ELA-LITERACY.SL.11-12.1 — Initiate and participate effectively in collaborative discussions. Direct Connection: Students discuss experimental controls, evidence categories, and scientific uncertainty. Measurable Skill: Students contribute one evidence-based interpretation and respond to a peer's reasoning. Justification: Teacher discussion prompts require collaborative analysis and revision of conclusions through evidence.
C3 Framework
D2.His.10.9-12 — Detect possible limitations in various kinds of historical evidence and differing secondary interpretations. Direct Connection: Students apply the broader evidence-evaluation skill to distinguish observed results from interpretations and proposed functions. Measurable Skill: Students identify one limitation in extending the study's findings to newborn-puppy behavior. Justification: Assessment Question 2 requires students to evaluate the limits of available evidence rather than accept a plausible interpretation as proven.
ISTE Standards
ISTE 1.3.d — Knowledge Constructor: Build knowledge by actively exploring real-world issues and problems, developing ideas and theories, and pursuing answers and solutions. Direct Connection: Students examine a real sensory biology investigation and generate follow-up research questions. Measurable Skill: Students formulate a testable question or controlled follow-up investigation. Justification: The extension and exit ticket move students from information recall to self-directed scientific inquiry.
Career Readiness Competencies
Analytical Thinking — Evaluate information, variables, and evidence before reaching a conclusion. Direct Connection: Students compare behavioral and neurological evidence. Measurable Skill: Students classify claims as evidence, interpretation, or hypothesis. Justification: This competency is directly practiced in the formative checkpoint and assessment.
Communication — Express technical information accurately for an audience. Direct Connection: Students use scientific vocabulary in written and collaborative responses. Measurable Skill: Students accurately use rhinarium, thermal radiation, and stimulus in an evidence-based explanation. Justification: Worksheet and discussion tasks measure precise scientific communication.
Problem Solving — Identify obstacles to reliable conclusions and propose controlled approaches. Direct Connection: Students identify possible confounding variables in sensory testing. Measurable Skill: Students propose at least one control for a follow-up experiment. Justification: The engagement strategy and extension require practical experimental reasoning.
Adaptability — Revise an interpretation when evidence limits an initial assumption. Direct Connection: Students examine why a plausible puppy-benefit explanation remains untested. Measurable Skill: Students revise absolute claims into appropriately qualified scientific statements. Justification: The lesson explicitly emphasizes intellectual flexibility in response to evidence limits.
Professional Judgment — Distinguish supported conclusions from speculation. Direct Connection: Students evaluate the wording used to describe direct findings and hypotheses. Measurable Skill: Students correctly identify one supported conclusion and one unresolved claim. Justification: The exit ticket directly measures disciplined judgment applicable to research and professional decision making.
Homeschool / Lifelong Learning Alignment
Independent Learning — Organize information from an audio or written source without continuous instructor direction. Direct Connection: Students independently identify structure, stimulus, and evidence during the first listening. Measurable Skill: Students produce accurate notes in all three categories. Justification: The audio-first task builds independent information-processing habits.
Information Literacy — Evaluate the strength and limits of scientific information. Direct Connection: Students distinguish experimental findings from proposed biological functions. Measurable Skill: Students explain why the puppy hypothesis requires additional direct testing. Justification: Analysis Question 4 and Assessment Question 2 directly measure evidence literacy.
Real-World Application — Connect scientific reasoning to practical research and decision-making contexts. Direct Connection: Students examine controls, imaging evidence, and research limitations. Measurable Skill: Students explain how controlling variables improves confidence in a conclusion. Justification: The experiment analysis transfers directly to evidence-based problem solving.
Self-Directed Inquiry — Generate questions that extend beyond presented information. Direct Connection: Students identify an unanswered question or design a follow-up investigation. Measurable Skill: Students formulate one testable research question. Justification: The extension and exit ticket encourage inquiry beyond passive content consumption.
Transferable Life Skills — Apply reasoning, communication, and judgment across contexts. Direct Connection: Students practice separating observation from assumption. Measurable Skill: Students support a decision or conclusion with evidence and state a limitation. Justification: This reasoning process is transferable to education, employment, consumer decisions, and everyday information evaluation.
Show Notes
A dog's nose may do more than detect scent. This episode explores research indicating that the canine rhinarium can respond to weak thermal radiation from warm objects. Students examine behavioral testing, functional MRI evidence, experimental controls, and the important distinction between demonstrated findings and plausible hypotheses. The lesson connects animal biology with neuroscience, physics, evidence evaluation, and scientific reasoning, showing why disciplined testing matters when researchers investigate abilities humans cannot directly experience.
References
Bálint, A., Andics, A., Gácsi, M., Gábor, A., Czeibert, K., Luce, C. M., Miklósi, Á., & Kröger, R. H. H. (2020). Dogs can sense weak thermal radiation. Scientific Reports, 10, Article 3736. https://doi.org/10.1038/s41598-020-60439-y
Katz, B. (2020, March 4). Dogs' cool, wet noses may be able to detect heat. Smithsonian Magazine. https://www.smithsonianmag.com/smart-news/dogs-cool-noses-may-be-able-detect-heat-180974321/
Purina Canada. (2024, May 29). When do puppies open their eyes? https://www.purina.ca/articles/puppy/health/when-do-puppies-open-their-eyes
