Misconceptions About Temperature

When touching objects, people perceive different temperatures based on how they feel, but this perception may not reflect actual temperature.

• A metal hard drive and a book are compared for temperature • Most people believe the hard drive feels colder than the book • People are confident in their perception and willing to argue about it

An infrared thermometer shows both objects are at exactly 19.0 degrees, the same temperature despite feeling different.

If both objects are the same temperature, why does one feel significantly colder than the other?

An aluminium block and a plastic block are compared; the aluminium feels much colder despite being the same temperature.

• Ice cubes are placed on both the aluminium and plastic blocks • The ice melts faster on the aluminium block than the plastic block • This contradicts the expectation that the colder-feeling material would keep ice solid longer

The difference is due to thermoconductivity—the rate at which heat transfers from one object to another.

• Aluminium conducts heat to the ice cube faster than plastic • The plastic block is a worse thermoconductor, so heat transfers more slowly • This causes the ice to melt faster on aluminium despite both blocks being the same temperature

You do not actually feel temperature when touching something; you feel the rate at which heat is conducted toward or away from your hand.

• The hard drive felt colder because aluminium conducts heat away from your hand faster than a book • The book felt warmer because it conducts heat away from your hand more slowly • Both were at the same actual temperature

After a shower in winter, a bath mat feels nicer to stand on than a towel because the mat conducts heat less quickly away from your body.

The perception of warmth or coldness depends on thermal conductivity, not actual temperature.