How hot or cold, and how we measure it. Read, drag the thermometer, sort, then play.
What it is
How hot or cold a thing is, is its temperature. We cannot judge it exactly by touch, because our hands can be fooled.
Why it works
After holding something cold, ordinary water can feel warm, and after something hot it can feel cool, so touch is not a reliable measure.
Why it matters
This is why we need a proper measuring tool instead of our hands.
A few examples
Warm water feels hot to a cold hand but cool to a warm hand, yet its temperature is the same.
What it is
A thermometer measures temperature. Temperature is usually measured in degrees Celsius (°C). A thin red or silver line rises as it gets hotter.
Why it works
The line moves up when heated and down when cooled, and the number it reaches on the scale is the temperature, giving an exact value.
Why it matters
This gives everyone the same reading, unlike a guess by touch.
A few examples
A thermometer reads in degrees Celsius. The line rises when things get hotter.
What it is
We can sort things around us into hot and cold, though only a thermometer tells us the exact temperature.
Why it works
Grouping by hot and cold builds our sense of temperature, which the thermometer then measures precisely.
Why it matters
This everyday sense keeps us safe around very hot or very cold things.
A few examples
Ice, snow and cold drinks are cold. Hot tea, fire and boiling water are hot.
What it is
To read a thermometer, look at where the line stops on the scale, with your eye level with the mark, and read the number in degrees Celsius.
Why it works
Reading straight on avoids mistakes. A higher line means a higher temperature, so 40 °C is warmer than 20 °C.
Why it matters
Correct reading gives a temperature we can trust and compare.
A few examples
If the line stops at 30, the temperature is 30 °C. 40 °C is warmer than 20 °C.
What it is
Some temperatures are worth knowing: a healthy human body is about 37 °C, water freezes at about 0 °C, and water boils at about 100 °C.
Why it works
These fixed points act as landmarks. A body clearly above 37 °C usually means a fever, which is why doctors check temperature.
Why it matters
Knowing these helps us understand health and everyday heating and cooling.
A few examples
Normal body temperature is about 37 °C. Ice forms at 0 °C. Water boils at 100 °C.
What it is
A clinical thermometer checks body temperature (about 35 to 42 °C). Clean it, read it at eye level, and never place it near a flame or in boiling water beyond its range.
Why it works
Thermometers are delicate, so gentle, correct use keeps them accurate and safe, and a broken one should be handled by an adult.
Why it matters
Safe habits protect both the thermometer and us.
A few examples
Clean and read at eye level. Keep it away from flame. If it breaks, tell an adult.
Slide to change the temperature. Watch the red column rise, read the value, and see the zone. It demos on its own until you touch it.
Drag each thing into hot or cold. sorted 0/6
Have a go first, then tap to see the clear steps.
Q1. Can we tell the exact temperature of water just by touching it?
Q2. In which unit is temperature commonly measured?
Q3. What is the normal temperature of a healthy human body?
Q4. A thermometer line stops at the mark 30. What is the temperature?
Q5. At about what temperature does water boil?
Q6. Which thermometer is used to check body temperature?