Temperature and its Measurement: common misconceptions

If your child says… “My hands always tell me how hot something is.”

Ask together

If your hands disagree about this water, can touch tell us its temperature reliably?

What’s true

The same water can feel different to hands coming from warmer and colder water.

If your child says… “Anything except 37.0 °C means illness.”

Ask together

If healthy people's temperatures vary, must every reading match?

What’s true

A reading slightly different from 37.0 °C does not always mean someone is ill.

If your child says… “The same number means the same temperature.”

Ask together

If one temperature has different numbers on these scales, is the number alone enough?

What’s true

37.0 °C equals 98.6 °F, rather than 37.0 °F.

If your child says… “Every little gap means 1 °C.”

Ask together

How much temperature does each equal gap represent?

What’s true

The value of a small division depends on that thermometer's scale.

If your child says… “I'll lift it out to read it.”

Ask together

Once the bulb leaves the water, what is touching it?

What’s true

Outside the water, the column starts changing, so it no longer reliably shows that water's temperature.

If your child says… “Heating always makes the temperature rise.”

Ask together

While the reading stays steady, what happens to the ice?

What’s true

At constant pressure, pure water keeps a steady temperature during melting or boiling.

If your child says… “Temperature alone tells us the weather forecast.”

Ask together

What other information would a weather station still need?

What’s true

Air temperature is only one measurement used for forecasting.