Science
What is the difference between heat and temperature?
Quick answer
Temperature tells you how hot or cold something is. Heat is energy that flows from a hotter thing to a cooler one. They are linked, but they are not the same.
In one sentence
Temperature measures how hot something is, and heat is the energy that moves from a hotter place to a colder one.
Explained
Everything is made of tiny particles that are always moving. The faster they move, the hotter the object is. Temperature tells you how fast the particles are moving on average. We measure it in degrees Celsius (°C) with a thermometer. Water freezes at 0 °C and boils at 100 °C, and a healthy human body is about 37 °C.
Heat is a form of energy. It is the energy that moves from a hotter object to a cooler one because of the difference in temperature. Heat always flows from hot to cold, never the other way, until both are at the same temperature. That is why a cup of tea cools down and an ice cube in your hand melts.
Temperature and heat are different. A cup of boiling water and a bath of warm water: the cup is at a higher temperature, but the bath contains much more heat energy, because it has far more water. A bath would melt a lot more ice than the cup.
sun
fire
mug
Heat travels in three ways:
- Conduction: through solids, from particle to particle. A spoon in hot tea gets hot. Metals conduct best; see conductors and insulators.
- Convection: in liquids and gases. Warm fluid rises and cool fluid sinks, creating a current, as in a boiling pot or a room with a radiator.
- Radiation: heat carried by invisible waves, called infrared. You feel it from a fire or the Sun. It can travel through empty space.
Heating makes particles move faster, and cooling slows them down. That is why heating a solid can make it melt: see melting and freezing. Heat is one form of energy. Materials called insulators slow heat flow, and we use them in coats, ovens and houses.
Examples
| Thing | Temperature |
|---|---|
| Freezer | about −18 °C |
| Freezing water | 0 °C |
| Human body | about 37 °C |
| Boiling water | 100 °C |
| Surface of the Sun | about 5,500 °C |
Common mistakes
- Mixing up heat and temperature. A spark is very hot but has little heat energy.
- "Cold flows into a warm room." It is the heat that flows out.
- Thinking a thermometer measures heat. It measures temperature.
Quick quiz
Heat and temperature
Check what you know with 4 quick questions.
Question 1 of 4
Which instrument measures temperature?
Practise it
Try it
Physics practice
Practise it step by step in a full course: Grade 5 Science
For grown-ups
Related topics
Energy
Energy is what makes things happen: it makes things move, heat up, light up and grow. It cannot be created or destroyed, only changed from one form to another.
Melting and freezing
Melting is when a solid turns into a liquid as it heats up. Freezing is when a liquid turns into a solid as it cools. Water melts and freezes at 0 degrees Celsius.
Materials
Materials are what objects are made from, such as wood, metal, plastic and glass. Each has properties, like being hard, bendy, waterproof or see-through, that suit it to some jobs.
Electric circuits
An electric circuit is a complete loop that electricity flows around. A simple circuit has a battery, wires and a component like a bulb. If the loop is broken, the electricity stops.
Electricity
Electricity is the flow of tiny charged particles called electrons through a material. It powers lights, phones and machines, and it can come from batteries or the mains supply.
Forces
A force is a push or a pull. Forces can make things start moving, speed up, slow down, change direction or change shape. They are measured in newtons.