What are the key takeaways from this Radiolab episode?

Key insights include: **Kleptothermy efficiency:** Animals stealing warmth from other creatures reduce thermoregulation costs by 60-70% compared to generating their own heat through movement or metabolism. Blue sea snakes curl around tropical seabirds without eating them, male garter snakes fake being female for mating friction warmth, and humans historically slept nine people per bed for survival.; **Schizophrenia temperature regulation:** Research by Dr. Mahindamani found patients with schizophrenia wearing redundant clothing in summer heat have measurably lower T3 and T4 hormone levels and blood pressure, indicating actual cold intolerance rather than confusion. Those wearing excessive layers had gone longer without treatment, suggesting visible layering behavior signals untreated mental illness requiring intervention.; **Social exclusion physical effects:** The cyberball experiment demonstrates that social rejection causes measurable drops in peripheral skin temperature, not just perceived coldness. When participants were excluded from a virtual ball-tossing game, digital thermometers recorded actual temperature decreases on their fingers, revealing how emotional states directly alter physiological temperature regulation through observable physical changes.

What did Hans Isermann and Tatagata Mahindamani discuss on Radiolab?

Radiolab explores kleptothermy (heat theft) across species and humans, revealing how body temperature connects to social isolation, mental health, and survival. The episode examines schizophrenia patients wearing excessive layers, the myth of 98.6°F as normal temperature, and how social connection directly influences core body temperature regulation. Key topics include: **Kleptothermy efficiency:** Animals stealing warmth from other creatures reduce thermoregulation costs by 60-70% compared to generating their own heat through movement or metabolism. Blue sea snakes curl around tropical seabirds without eating them, male garter snakes fake being female for mating friction warmth, and humans historically slept nine people per bed for survival.; **Schizophrenia temperature regulation:** Research by Dr. Mahindamani found patients with schizophrenia wearing redundant clothing in summer heat have measurably lower T3 and T4 hormone levels and blood pressure, indicating actual cold intolerance rather than confusion. Those wearing excessive layers had gone longer without treatment, suggesting visible layering behavior signals untreated mental illness requiring intervention..

How long is this episode of Radiolab?

This episode is 43 minutes long. SignalCast provides an AI-generated summary so you can get the key insights in about 3 minutes.

Radiolab

Kleptotherms

February 6, 2026

43 min episode · 2 min read

Hans Isermann,Tatagata Mahindamani

Episode

43 min

Read time

2 min

Topics

Productivity, Health & Wellness, Relationships

AI-Generated Summary

Published Feb 6, 2026

Key Takeaways

✓Kleptothermy efficiency: Animals stealing warmth from other creatures reduce thermoregulation costs by 60-70% compared to generating their own heat through movement or metabolism. Blue sea snakes curl around tropical seabirds without eating them, male garter snakes fake being female for mating friction warmth, and humans historically slept nine people per bed for survival.
✓Schizophrenia temperature regulation: Research by Dr. Mahindamani found patients with schizophrenia wearing redundant clothing in summer heat have measurably lower T3 and T4 hormone levels and blood pressure, indicating actual cold intolerance rather than confusion. Those wearing excessive layers had gone longer without treatment, suggesting visible layering behavior signals untreated mental illness requiring intervention.
✓Social exclusion physical effects: The cyberball experiment demonstrates that social rejection causes measurable drops in peripheral skin temperature, not just perceived coldness. When participants were excluded from a virtual ball-tossing game, digital thermometers recorded actual temperature decreases on their fingers, revealing how emotional states directly alter physiological temperature regulation through observable physical changes.
✓Temperature measurement variability: Human body temperature varies by six degrees across healthy individuals based on sex, age, height, body composition, time of day, and measurement location. Women run hotter than men, taller people cooler, and readings from ear, armpit, and rectum differ by two degrees. Temperature guns used for COVID screening read 2-3 degrees cooler than actual temperature.
✓Social network temperature correlation: Research analyzing core body temperature predictors found diversity of social networks (having work friends, family, hobby groups, not just quantity of friends) ranked higher than body weight or height in determining baseline temperature. Multiple social group types provide backup support, reducing physiological stress responses that lower body temperature when isolation threatens survival.

What It Covers

Radiolab explores kleptothermy (heat theft) across species and humans, revealing how body temperature connects to social isolation, mental health, and survival. The episode examines schizophrenia patients wearing excessive layers, the myth of 98.6°F as normal temperature, and how social connection directly influences core body temperature regulation.

Key Questions Answered

•Kleptothermy efficiency: Animals stealing warmth from other creatures reduce thermoregulation costs by 60-70% compared to generating their own heat through movement or metabolism. Blue sea snakes curl around tropical seabirds without eating them, male garter snakes fake being female for mating friction warmth, and humans historically slept nine people per bed for survival.
•Schizophrenia temperature regulation: Research by Dr. Mahindamani found patients with schizophrenia wearing redundant clothing in summer heat have measurably lower T3 and T4 hormone levels and blood pressure, indicating actual cold intolerance rather than confusion. Those wearing excessive layers had gone longer without treatment, suggesting visible layering behavior signals untreated mental illness requiring intervention.
•Social exclusion physical effects: The cyberball experiment demonstrates that social rejection causes measurable drops in peripheral skin temperature, not just perceived coldness. When participants were excluded from a virtual ball-tossing game, digital thermometers recorded actual temperature decreases on their fingers, revealing how emotional states directly alter physiological temperature regulation through observable physical changes.
•Temperature measurement variability: Human body temperature varies by six degrees across healthy individuals based on sex, age, height, body composition, time of day, and measurement location. Women run hotter than men, taller people cooler, and readings from ear, armpit, and rectum differ by two degrees. Temperature guns used for COVID screening read 2-3 degrees cooler than actual temperature.
•Social network temperature correlation: Research analyzing core body temperature predictors found diversity of social networks (having work friends, family, hobby groups, not just quantity of friends) ranked higher than body weight or height in determining baseline temperature. Multiple social group types provide backup support, reducing physiological stress responses that lower body temperature when isolation threatens survival.

Notable Moment

A Stanford researcher discovered the average human body temperature has dropped 0.05 degrees Fahrenheit every decade since the 1850s, meaning the canonical 98.6°F is outdated. Current Western population average sits at 97.5°F, possibly due to better infection control, changing demographics, and reduced baseline inflammation from improved medical care.

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Episode Transcript

WNYC Studios is supported by Odoo. When you buy business software from lots of vendors, the costs add up and it gets complicated and confusing. Odoo solves this. It's a single company that sells a suite of enterprise apps that handles everything from accounting to inventory to sales. Odoo is all connected on a single platform in a simple and affordable way. You can save money without missing out on the features you need. Check out Odoo at odoo.com. That's odoo.com. Hey. This is Radiolab. I'm Latif Nasir. So at this point of the year, at least here in the Northern Hemisphere, it can start to feel like enough with the cold already. The newness of the season has worn off. The winter holidays are over, and most of us are just ready for it to be warm again. So today, we are defrosting an episode about people and creatures seeking warmth. Sometimes they do it in obvious ways. Sometimes they do it in devious ways. We first aired this episode back in 2021, and you'll hear there are certain things about it that do feel very twenty twenty one, but there's also so much in here that feels timeless. Stories that I feel confident will stay relevant until the thermal death of the universe. Yep. You're wait. Wait. You're listening. K. Alright. K. Alright. You're listening Listening. To Radio Lab. Radio Lab. From WNYC. W n y See? Yep. Rewind. Lou. Hey. How are you feeling? I I mean, I feel fine. I think I still am like a dashed nasally hi there. It's Radiolab. I'm Lulu Miller here with senior correspondent Molly Webster. So can you humor me and close your eyes? Yes. Eyes closed in my closet. Okay. So now journey with me. Me and you are on a trip. We've got our backpacks and our hiking boots. Okay. And we've we come across this site Mhmm. An archaeological dig. And they are they're, like, unearthing this ancient library. And we're, like, looking all around, and you're over there, and I don't know, you find, like, a old globe. And then we come across this book that's, like, covered in dust, and we blow the dust off. And the dust, like, it turns into, like, snowy, frosty snowflakes and little tiny flames. -Oh. -It's like And then it says in silver letters, kleptotherms. And then we were like, oh, what's what? What? And we crack the book, and it's like, and we open it. And there's five chapters. And we turn the page, and the first chapter, there's just a picture of a snake in a coil. So we're gonna start and read that chapter. -Okay. So once upon a time, there was a bright blue snake in New Caledonia. It's bright blue and black, so it's just like straight up. Is this real? This is real. Oh, this is one of the Okay. This is Oh, it turns out this whole book is stored in the …

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