Why some people never feel the cold even when it’s below zero degrees

Parts of Australia are shivering through our coldest June weather in five years, but we still see people walking outside in just T-shirts and shorts. Why don’t they feel the cold?

Scientists say there are several reasons. Some people are born with special genes* to deal with below-zero temperatures while, for others, exercising in the morning and having good blood circulation* helps keep them warmer on chilly days.

Research has found one in five people have a specific genetic mutation* that is linked to a higher resilience* to cold temperatures.

Mutations are a change in our genetic code called DNA, and can sometimes lead to mistakes in how proteins are made in our bodies.

The 2021 study showed people who are missing a protein called alpha-actinin-3 in their muscles shiver less and maintain a higher inner-body temperature in icy environments.

The gene mutation became more common as humans began to migrate from Africa into colder temperatures in Europe more than 50,000 years ago.

“Our study shows an improved cold tolerance in people lacking alpha-actinin-3, which would have been an evolutionary* survival advantage when moving to colder climates,” one of the study authors Håkan Westerblad of the Karolinska Institute said.

For the rest of us who have normal genes, a shift to morning exercise could keep us warmer.

Australian food scientist and researcher Dr Vincent Candrawinata said people who regularly work out first thing in the morning will typically be warmer all day.

“People who are active and exercising every day, they’re actually less prone* towards feeling cold because their body is so used to producing a higher amount of heat compared to people who don’t really exercise,” Dr Candrawinata said.

He said poor blood flow to the body’s extremities* could also affect body warmth.

“It’s why some people don’t necessarily feel cold, but always have very cold hands or feet,” he said.

POLL

GLOSSARY

• genes: they carry the information that determines your features or characteristics that are passed on to you from your parents.
• circulation: movement of blood through the heart and around the body.
• genetic mutation: a change in the genetic code, DNA, that can sometimes lead to proteins being made wrong.
• resilience: the ability to cope with something uncomfortable or when things go wrong.
• DNA: stands for deoxyribonucleic acid. DNA is the genetic information inside the body’s cells that helps make people who they are
• evolutionary: how living things change to adapt to new environments
• prone: being likely to
• extremities: arms, legs, hands and feet.

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QUICK QUIZ
1. What happens to people who are missing the protein called alpha-actinin-3 in their muscles?
2. When did the gene mutation become more common?
3. How did the mutation help humans survive?
4. How does morning exercise help us stay warm?
5. Why do some people always have cold hands and feet?

LISTEN TO THIS STORY

CLASSROOM ACTIVITIES
1. Winter Warmers
Design a series of exercises to keep warm during these cold winter mornings. Aim for a 10-minute exercise session to get the blood flowing.
You could do them with your family each morning, or take them into the classroom to do before class starts each morning, ready for the day’s learning.

Take note of how you feel now on a cold morning, and compare it to how you feel after doing some exercise on a cold morning.
Write your exercise plan below with sketches.

Time: allow 30 minutes to complete this activity
Curriculum Links: English, Health and Physical education, Personal and social, Critical and creative thinking.

2. Extension
This might explain why some school kids can wear shorts and T-shirts all year round, even on very cold days!
Some adults or schools insist that kids need to wear jackets and pants to keep warm. Do you think the evidence in this story can prove otherwise?
Is it less or more healthy to not feel the cold as much do you think?

Time: allow 15 minutes to complete this activity
Curriculum Links: English, Science, Critical and creative thinking.

VCOP ACTIVITY
1. To sum it up
After reading the article, use your comprehension skills to summarise in a maximum of three sentences what the article is about.
Think about:

• What is the main topic or idea?
• What is an important or interesting fact?
• Who was involved (people or places)?

Use your VCOP skills to re-read your summary to make sure it is clear, specific and well-punctuated.