Why am I warm blooded?

Why am I warm blooded?

Author: BBC World Service August 21, 2026 Duration: 26:28

CrowdScience listener Matt wants to know why he's warm blooded. He started thinking about this when he was watching some ants during the recent heatwave in Europe and wondered why their blood didn't boil. What are the pros and cons of being warm-blooded like us or cold-blooded reptiles like lizards?

Caroline Steel meets evolutionary biologist Dr Manuel Leal from the University of Missouri in the US, who explains the differences between ectotherms (cold-blooded animals) and endotherms (warm-blooded animals). She discovers that the terms cold blooded and warm blooded are actually misleading, because reptiles can reach a high body temperature and some might even become warmer than us.

She talks to Simon Hodder, Professor of Environmental Ergonomics at Loughborough University in the UK, who describes how our bodies regulate heat, how we cool down when we get too warm and how that's all controlled by our brains.

Caroline also gets to meet some hedgehogs in the wild with Julia Nowack, an ecophysiologist from Liverpool John Moores University, who researches thermoregulation and is monitoring hedgehogs when they hibernate. Changing body temperature is one of the ways that some endotherms survive the winter when it's colder and there's less food around.

So who has the advantage? The warm-blooded endotherms who can heat their own bodies or the cold-blooded ectotherms who rely on the sun? Reptiles can get away with eating very occasionally while mammals and birds have to keep fuelling their energy with food to keep the heat going. That means we can live in most climates and have a better chance of escaping predators, but is it really best?

Presenter: Caroline Steel

Producer: Jo Glanville

Editor: Ben Motley

(Photo: European hedgehog (Erinaceus europaeus) adult animal in a snow covered garden in winter, England, United Kingdom - stock photo Credit: imageBROKER/Kevin Sawford via Getty Images)


Curiosity drives discovery, and CrowdScience from the BBC World Service is built entirely on that principle. Each episode begins not with a scripted lesson, but with a question sent in by a listener from anywhere in the world. These aren't simple queries with easy answers; they are the wonderfully complex, often quirky puzzles about everyday phenomena and cosmic mysteries that make us all stop and wonder. What does silence sound like? Could we ever photosynthesize like plants? How does a crowd's mood physically spread? The team then embarks on a genuine investigative journey, tracking down the specialists at the very edge of our understanding-neuroscientists, ecologists, physicists, and engineers-to piece together credible, compelling answers. Listening to this podcast feels like having a direct line to the labs and field sites where knowledge is being created. The conversations are deep yet accessible, transforming abstract concepts into relatable stories. It’s a collective exploration where listener curiosity sets the agenda, making each episode a unique and democratic look at the machinery of our world and beyond. You become part of a global community pondering life, Earth, and the universe, one thoughtful question at a time.
Author: Language: English Episodes: 50

CrowdScience
Podcast Episodes
How did plants evolve to attract insects? [not-audio_url] [/not-audio_url]

Duration: 26:28
Many plants need pollen from another plant of the same species in order to reproduce, but they don’t have legs so they can’t simply walk around looking for a mate. As a result, many of them rely on animals to transfer po…
Do animals care about the past? [not-audio_url] [/not-audio_url]

Duration: 26:28
“What separates humans from animals, is an interest in the past”. That’s a 900-year-old quote from a textbook that Nigerian listener Taiwo came across, and he wrote to CrowdScience to ask if modern science would agree. M…
How does Bluetooth work? [not-audio_url] [/not-audio_url]

Duration: 26:30
CrowdScience listener Rachel uses Bluetooth headphones on her cycle to work, seamlessly playing music from her phone without using wires. But how does this technology send information through the air? To find out, Rachel…
Why does paper fold so well? [not-audio_url] [/not-audio_url]

Duration: 26:29
CrowdScience listener Haruka has been making origami cranes out of paper since she was a child. Creating one out of a cloth napkin, however, was a next-level challenge. It gave her a new appreciation of paper’s excellent…
Do plants have personalities? [not-audio_url] [/not-audio_url]

Duration: 29:16
CrowdScience listener George is showing Alex Lathbridge around a small, dark, and extremely hot shed, just outside the city of Accra in Ghana. Inside are row after row of shelves, stacked high with bulging grow-bags. And…
What's the deal with tongues? [not-audio_url] [/not-audio_url]

Duration: 26:28
Why is there such a variety of tongues in the animal kingdom? CrowdScience listener Dale has observed that his dog’s tongue is different from his and so is his cat’s. He’d like to know the reason. Caroline Steel visits L…
Why am I an introvert? [not-audio_url] [/not-audio_url]

Duration: 26:28
CrowdScience listener Daniel in Accra, Ghana is an introvert. Or at least, he thinks he is. And he’s worried that his preference for quiet spaces and lower social interaction might be holding him back in life. But what i…
Why do we itch? [not-audio_url] [/not-audio_url]

Duration: 26:28
Why do we feel itchy? So many listeners have emailed in with questions about itchiness, and presenter Anand Jagatia on the case. We explore why we itch, the different types of itch, the different causes, and why scratchi…
How come sea levels are rising faster in some places than others? [not-audio_url] [/not-audio_url]

Duration: 31:24
As our oceans warm due to climate change, sea levels are rising. It ought to be straightforward – as water gets warmer, it increases in volume. All the world’s oceans are connected, so how come sea levels are rising at d…
Why can't I recognise faces? [not-audio_url] [/not-audio_url]

Duration: 26:28
CrowdScience listener Jeroen finds it hard to remember people's faces - and he wants to know why. He wonders if it's to do with getting older and if there’s any way of improving. Presenter Caroline Steel has the same pro…