NCERT Textbook: Temperature and its Measurement | Science Class 6 PDF Download

 Page 1


Temperature and  
its Measurement
7 Chapter
Lambok and his elder sister 
Phiban live in Shillong. One day 
they came home from school. 
Their parents were away at 
work and Lambok complained 
that he was feeling feverish. 
Phiban touched his forehead 
and felt that he might be 
having a fever . To confirm this, 
she took out the thermometer 
kept in the almirah. She 
washed its tip with soap and 
water, and measured Lambok’s 
temperature. To her relief, she 
found that his temperature 
was normal. She washed the 
thermometer tip again, dried 
Wrong measurements are worse than 
no measurements at all. 
— Anna Mani
7.1 Hot or Cold?
We know from experience that some bodies are hotter than 
others. For example, during summers, the tap water may be 
hotter than the cold water from a matka (earthen pot) or a 
it and put it back. She then asked 
Lambok to change his school 
uniform, eat his lunch, and rest for 
some time. 
Can it always be 
correctly judged, that 
a person has fever, 
only by touching the 
person?
?
Chapter 7.indd   123 10-07-2024   12:50:47
Page 2


Temperature and  
its Measurement
7 Chapter
Lambok and his elder sister 
Phiban live in Shillong. One day 
they came home from school. 
Their parents were away at 
work and Lambok complained 
that he was feeling feverish. 
Phiban touched his forehead 
and felt that he might be 
having a fever . To confirm this, 
she took out the thermometer 
kept in the almirah. She 
washed its tip with soap and 
water, and measured Lambok’s 
temperature. To her relief, she 
found that his temperature 
was normal. She washed the 
thermometer tip again, dried 
Wrong measurements are worse than 
no measurements at all. 
— Anna Mani
7.1 Hot or Cold?
We know from experience that some bodies are hotter than 
others. For example, during summers, the tap water may be 
hotter than the cold water from a matka (earthen pot) or a 
it and put it back. She then asked 
Lambok to change his school 
uniform, eat his lunch, and rest for 
some time. 
Can it always be 
correctly judged, that 
a person has fever, 
only by touching the 
person?
?
Chapter 7.indd   123 10-07-2024   12:50:47
 Curiosity | Textbook of Science| Grade 6
124
refrigerator . We can realise this by merely touching the two 
samples of water. But can we always rely upon our sense of 
touch? Let us find out.
Activity 7.1: Let us investigate
 ? Take three large containers and label them A, B and C, 
as shown in Fig. 7.1.
 ? Pour warm water in container A, tap water in B and ice-
cold water in C. 
 ? We will conduct this activity in two parts — prediction 
and observation.
 ? Firstly, predict what will you feel if you 
 — dip your right hand in A and left hand in C and 
keep them there for 1–2 minutes.
 — take out your hands from containers A and C, and 
place both hands simultaneously in B.
Compare whether your observations match with your 
predictions. Did your right hand feel that the water in 
container B is cool, while your left hand felt that 
the same water is warm? What do you infer 
from these observations?
We cannot always rely upon our sense of 
touch to decide correctly whether a body is 
hot or cold. 
7.2 Temperature
A reliable measure of hotness (or coldness) of a body is 
its temperature. A hotter body has a higher temperature 
than a colder body.  The difference in temperature between 
the two bodies tells us how hot a body is in comparison to 
another body.  A device that measures temperature is called 
a thermometer.
There are two kinds of thermometers that you are likely 
to come across—clinical thermometers and laboratory 
thermometers. Clinical thermometers are used to 
measure human body temperatures whereas laboratory 
thermometers are used for many other purposes. Let us 
now learn more about thermometers and how to use them 
to measure temperature. 
7.3  Measuring Temperature
7.3.1 Clinical thermometer
You might be familiar with a thermometer , like that shown in 
Fig. 7.2, which is used for measuring our body temperature. 
It is called a clinical thermometer . Such thermometers show 
temperatures digitally. These are also known as digital 
clinical thermometers and run on batteries. These measure 
 ? Write down your predictions.
 — What will my right hand feel on dipping in B? 
   
 — What will my left hand feel on dipping in B? 
   
 ? Now, conduct the activity and write your observations.
               
Fig. 7.1: Feeling hotness or coldness of water by dipping hands
A B C A B C
Chapter 7.indd   124 10-07-2024   12:50:48
Page 3


Temperature and  
its Measurement
7 Chapter
Lambok and his elder sister 
Phiban live in Shillong. One day 
they came home from school. 
Their parents were away at 
work and Lambok complained 
that he was feeling feverish. 
Phiban touched his forehead 
and felt that he might be 
having a fever . To confirm this, 
she took out the thermometer 
kept in the almirah. She 
washed its tip with soap and 
water, and measured Lambok’s 
temperature. To her relief, she 
found that his temperature 
was normal. She washed the 
thermometer tip again, dried 
Wrong measurements are worse than 
no measurements at all. 
— Anna Mani
7.1 Hot or Cold?
We know from experience that some bodies are hotter than 
others. For example, during summers, the tap water may be 
hotter than the cold water from a matka (earthen pot) or a 
it and put it back. She then asked 
Lambok to change his school 
uniform, eat his lunch, and rest for 
some time. 
Can it always be 
correctly judged, that 
a person has fever, 
only by touching the 
person?
?
Chapter 7.indd   123 10-07-2024   12:50:47
 Curiosity | Textbook of Science| Grade 6
124
refrigerator . We can realise this by merely touching the two 
samples of water. But can we always rely upon our sense of 
touch? Let us find out.
Activity 7.1: Let us investigate
 ? Take three large containers and label them A, B and C, 
as shown in Fig. 7.1.
 ? Pour warm water in container A, tap water in B and ice-
cold water in C. 
 ? We will conduct this activity in two parts — prediction 
and observation.
 ? Firstly, predict what will you feel if you 
 — dip your right hand in A and left hand in C and 
keep them there for 1–2 minutes.
 — take out your hands from containers A and C, and 
place both hands simultaneously in B.
Compare whether your observations match with your 
predictions. Did your right hand feel that the water in 
container B is cool, while your left hand felt that 
the same water is warm? What do you infer 
from these observations?
We cannot always rely upon our sense of 
touch to decide correctly whether a body is 
hot or cold. 
7.2 Temperature
A reliable measure of hotness (or coldness) of a body is 
its temperature. A hotter body has a higher temperature 
than a colder body.  The difference in temperature between 
the two bodies tells us how hot a body is in comparison to 
another body.  A device that measures temperature is called 
a thermometer.
There are two kinds of thermometers that you are likely 
to come across—clinical thermometers and laboratory 
thermometers. Clinical thermometers are used to 
measure human body temperatures whereas laboratory 
thermometers are used for many other purposes. Let us 
now learn more about thermometers and how to use them 
to measure temperature. 
7.3  Measuring Temperature
7.3.1 Clinical thermometer
You might be familiar with a thermometer , like that shown in 
Fig. 7.2, which is used for measuring our body temperature. 
It is called a clinical thermometer . Such thermometers show 
temperatures digitally. These are also known as digital 
clinical thermometers and run on batteries. These measure 
 ? Write down your predictions.
 — What will my right hand feel on dipping in B? 
   
 — What will my left hand feel on dipping in B? 
   
 ? Now, conduct the activity and write your observations.
               
Fig. 7.1: Feeling hotness or coldness of water by dipping hands
A B C A B C
Chapter 7.indd   124 10-07-2024   12:50:48
Temperature and its Measurement
125
refrigerator . We can realise this by merely touching the two 
samples of water. But can we always rely upon our sense of 
touch? Let us find out.
Activity 7.1: Let us investigate
 ? Take three large containers and label them A, B and C, 
as shown in Fig. 7.1.
 ? Pour warm water in container A, tap water in B and ice-
cold water in C. 
 ? We will conduct this activity in two parts — prediction 
and observation.
 ? Firstly, predict what will you feel if you 
 — dip your right hand in A and left hand in C and 
keep them there for 1–2 minutes.
 — take out your hands from containers A and C, and 
place both hands simultaneously in B.
Compare whether your observations match with your 
predictions. Did your right hand feel that the water in 
container B is cool, while your left hand felt that 
the same water is warm? What do you infer 
from these observations?
We cannot always rely upon our sense of 
touch to decide correctly whether a body is 
hot or cold. 
7.2 Temperature
A reliable measure of hotness (or coldness) of a body is 
its temperature. A hotter body has a higher temperature 
than a colder body.  The difference in temperature between 
the two bodies tells us how hot a body is in comparison to 
another body.  A device that measures temperature is called 
a thermometer.
There are two kinds of thermometers that you are likely 
to come across—clinical thermometers and laboratory 
thermometers. Clinical thermometers are used to 
measure human body temperatures whereas laboratory 
thermometers are used for many other purposes. Let us 
now learn more about thermometers and how to use them 
to measure temperature. 
7.3  Measuring Temperature
7.3.1 Clinical thermometer
You might be familiar with a thermometer , like that shown in 
Fig. 7.2, which is used for measuring our body temperature. 
It is called a clinical thermometer . Such thermometers show 
temperatures digitally. These are also known as digital 
clinical thermometers and run on batteries. These measure 
Then how do we 
find out how hot 
or cold a body 
is? 
Fig.7.2: A digital clinical thermometer
Tip
Chapter 7.indd   125 10-07-2024   12:50:49
Page 4


Temperature and  
its Measurement
7 Chapter
Lambok and his elder sister 
Phiban live in Shillong. One day 
they came home from school. 
Their parents were away at 
work and Lambok complained 
that he was feeling feverish. 
Phiban touched his forehead 
and felt that he might be 
having a fever . To confirm this, 
she took out the thermometer 
kept in the almirah. She 
washed its tip with soap and 
water, and measured Lambok’s 
temperature. To her relief, she 
found that his temperature 
was normal. She washed the 
thermometer tip again, dried 
Wrong measurements are worse than 
no measurements at all. 
— Anna Mani
7.1 Hot or Cold?
We know from experience that some bodies are hotter than 
others. For example, during summers, the tap water may be 
hotter than the cold water from a matka (earthen pot) or a 
it and put it back. She then asked 
Lambok to change his school 
uniform, eat his lunch, and rest for 
some time. 
Can it always be 
correctly judged, that 
a person has fever, 
only by touching the 
person?
?
Chapter 7.indd   123 10-07-2024   12:50:47
 Curiosity | Textbook of Science| Grade 6
124
refrigerator . We can realise this by merely touching the two 
samples of water. But can we always rely upon our sense of 
touch? Let us find out.
Activity 7.1: Let us investigate
 ? Take three large containers and label them A, B and C, 
as shown in Fig. 7.1.
 ? Pour warm water in container A, tap water in B and ice-
cold water in C. 
 ? We will conduct this activity in two parts — prediction 
and observation.
 ? Firstly, predict what will you feel if you 
 — dip your right hand in A and left hand in C and 
keep them there for 1–2 minutes.
 — take out your hands from containers A and C, and 
place both hands simultaneously in B.
Compare whether your observations match with your 
predictions. Did your right hand feel that the water in 
container B is cool, while your left hand felt that 
the same water is warm? What do you infer 
from these observations?
We cannot always rely upon our sense of 
touch to decide correctly whether a body is 
hot or cold. 
7.2 Temperature
A reliable measure of hotness (or coldness) of a body is 
its temperature. A hotter body has a higher temperature 
than a colder body.  The difference in temperature between 
the two bodies tells us how hot a body is in comparison to 
another body.  A device that measures temperature is called 
a thermometer.
There are two kinds of thermometers that you are likely 
to come across—clinical thermometers and laboratory 
thermometers. Clinical thermometers are used to 
measure human body temperatures whereas laboratory 
thermometers are used for many other purposes. Let us 
now learn more about thermometers and how to use them 
to measure temperature. 
7.3  Measuring Temperature
7.3.1 Clinical thermometer
You might be familiar with a thermometer , like that shown in 
Fig. 7.2, which is used for measuring our body temperature. 
It is called a clinical thermometer . Such thermometers show 
temperatures digitally. These are also known as digital 
clinical thermometers and run on batteries. These measure 
 ? Write down your predictions.
 — What will my right hand feel on dipping in B? 
   
 — What will my left hand feel on dipping in B? 
   
 ? Now, conduct the activity and write your observations.
               
Fig. 7.1: Feeling hotness or coldness of water by dipping hands
A B C A B C
Chapter 7.indd   124 10-07-2024   12:50:48
Temperature and its Measurement
125
refrigerator . We can realise this by merely touching the two 
samples of water. But can we always rely upon our sense of 
touch? Let us find out.
Activity 7.1: Let us investigate
 ? Take three large containers and label them A, B and C, 
as shown in Fig. 7.1.
 ? Pour warm water in container A, tap water in B and ice-
cold water in C. 
 ? We will conduct this activity in two parts — prediction 
and observation.
 ? Firstly, predict what will you feel if you 
 — dip your right hand in A and left hand in C and 
keep them there for 1–2 minutes.
 — take out your hands from containers A and C, and 
place both hands simultaneously in B.
Compare whether your observations match with your 
predictions. Did your right hand feel that the water in 
container B is cool, while your left hand felt that 
the same water is warm? What do you infer 
from these observations?
We cannot always rely upon our sense of 
touch to decide correctly whether a body is 
hot or cold. 
7.2 Temperature
A reliable measure of hotness (or coldness) of a body is 
its temperature. A hotter body has a higher temperature 
than a colder body.  The difference in temperature between 
the two bodies tells us how hot a body is in comparison to 
another body.  A device that measures temperature is called 
a thermometer.
There are two kinds of thermometers that you are likely 
to come across—clinical thermometers and laboratory 
thermometers. Clinical thermometers are used to 
measure human body temperatures whereas laboratory 
thermometers are used for many other purposes. Let us 
now learn more about thermometers and how to use them 
to measure temperature. 
7.3  Measuring Temperature
7.3.1 Clinical thermometer
You might be familiar with a thermometer , like that shown in 
Fig. 7.2, which is used for measuring our body temperature. 
It is called a clinical thermometer . Such thermometers show 
temperatures digitally. These are also known as digital 
clinical thermometers and run on batteries. These measure 
Then how do we 
find out how hot 
or cold a body 
is? 
Fig.7.2: A digital clinical thermometer
Tip
Chapter 7.indd   125 10-07-2024   12:50:49
 Curiosity | Textbook of Science| Grade 6
126
Do you 
know?
Earlier, mercury thermometers were used for measuring 
the body temperature. But mercury is an extremely toxic 
substance and is difficult to dispose of if the thermometer 
breaks accidently. 
Digital thermometers pose no such risk and also the 
numbers in its display are easier to read. Therefore, 
mercury thermometers are being replaced by digital 
thermometers. Temperature in a digital thermometer 
is determined with the help of heat sensors. 
temperature when the thermometer is placed in contact 
with a person’s body.
For measuring temperature, the clinical thermometers 
generally use a scale called the Celsius scale. On this 
scale, the unit of temperature is degree Celsius and is 
denoted by °C.  
They are non-contact thermometers, 
also called infrared 
thermometers. Such 
thermometers can 
measure temperature 
without touching a 
person’s body and 
thus reduce the risk of 
spreading disease.
During the COVID-19 
pandemic, some special 
thermometers were used, 
which could measure the 
temperature of a person 
from a distance. What were 
those?
Chapter 7.indd   126 10-07-2024   12:50:58
Page 5


Temperature and  
its Measurement
7 Chapter
Lambok and his elder sister 
Phiban live in Shillong. One day 
they came home from school. 
Their parents were away at 
work and Lambok complained 
that he was feeling feverish. 
Phiban touched his forehead 
and felt that he might be 
having a fever . To confirm this, 
she took out the thermometer 
kept in the almirah. She 
washed its tip with soap and 
water, and measured Lambok’s 
temperature. To her relief, she 
found that his temperature 
was normal. She washed the 
thermometer tip again, dried 
Wrong measurements are worse than 
no measurements at all. 
— Anna Mani
7.1 Hot or Cold?
We know from experience that some bodies are hotter than 
others. For example, during summers, the tap water may be 
hotter than the cold water from a matka (earthen pot) or a 
it and put it back. She then asked 
Lambok to change his school 
uniform, eat his lunch, and rest for 
some time. 
Can it always be 
correctly judged, that 
a person has fever, 
only by touching the 
person?
?
Chapter 7.indd   123 10-07-2024   12:50:47
 Curiosity | Textbook of Science| Grade 6
124
refrigerator . We can realise this by merely touching the two 
samples of water. But can we always rely upon our sense of 
touch? Let us find out.
Activity 7.1: Let us investigate
 ? Take three large containers and label them A, B and C, 
as shown in Fig. 7.1.
 ? Pour warm water in container A, tap water in B and ice-
cold water in C. 
 ? We will conduct this activity in two parts — prediction 
and observation.
 ? Firstly, predict what will you feel if you 
 — dip your right hand in A and left hand in C and 
keep them there for 1–2 minutes.
 — take out your hands from containers A and C, and 
place both hands simultaneously in B.
Compare whether your observations match with your 
predictions. Did your right hand feel that the water in 
container B is cool, while your left hand felt that 
the same water is warm? What do you infer 
from these observations?
We cannot always rely upon our sense of 
touch to decide correctly whether a body is 
hot or cold. 
7.2 Temperature
A reliable measure of hotness (or coldness) of a body is 
its temperature. A hotter body has a higher temperature 
than a colder body.  The difference in temperature between 
the two bodies tells us how hot a body is in comparison to 
another body.  A device that measures temperature is called 
a thermometer.
There are two kinds of thermometers that you are likely 
to come across—clinical thermometers and laboratory 
thermometers. Clinical thermometers are used to 
measure human body temperatures whereas laboratory 
thermometers are used for many other purposes. Let us 
now learn more about thermometers and how to use them 
to measure temperature. 
7.3  Measuring Temperature
7.3.1 Clinical thermometer
You might be familiar with a thermometer , like that shown in 
Fig. 7.2, which is used for measuring our body temperature. 
It is called a clinical thermometer . Such thermometers show 
temperatures digitally. These are also known as digital 
clinical thermometers and run on batteries. These measure 
 ? Write down your predictions.
 — What will my right hand feel on dipping in B? 
   
 — What will my left hand feel on dipping in B? 
   
 ? Now, conduct the activity and write your observations.
               
Fig. 7.1: Feeling hotness or coldness of water by dipping hands
A B C A B C
Chapter 7.indd   124 10-07-2024   12:50:48
Temperature and its Measurement
125
refrigerator . We can realise this by merely touching the two 
samples of water. But can we always rely upon our sense of 
touch? Let us find out.
Activity 7.1: Let us investigate
 ? Take three large containers and label them A, B and C, 
as shown in Fig. 7.1.
 ? Pour warm water in container A, tap water in B and ice-
cold water in C. 
 ? We will conduct this activity in two parts — prediction 
and observation.
 ? Firstly, predict what will you feel if you 
 — dip your right hand in A and left hand in C and 
keep them there for 1–2 minutes.
 — take out your hands from containers A and C, and 
place both hands simultaneously in B.
Compare whether your observations match with your 
predictions. Did your right hand feel that the water in 
container B is cool, while your left hand felt that 
the same water is warm? What do you infer 
from these observations?
We cannot always rely upon our sense of 
touch to decide correctly whether a body is 
hot or cold. 
7.2 Temperature
A reliable measure of hotness (or coldness) of a body is 
its temperature. A hotter body has a higher temperature 
than a colder body.  The difference in temperature between 
the two bodies tells us how hot a body is in comparison to 
another body.  A device that measures temperature is called 
a thermometer.
There are two kinds of thermometers that you are likely 
to come across—clinical thermometers and laboratory 
thermometers. Clinical thermometers are used to 
measure human body temperatures whereas laboratory 
thermometers are used for many other purposes. Let us 
now learn more about thermometers and how to use them 
to measure temperature. 
7.3  Measuring Temperature
7.3.1 Clinical thermometer
You might be familiar with a thermometer , like that shown in 
Fig. 7.2, which is used for measuring our body temperature. 
It is called a clinical thermometer . Such thermometers show 
temperatures digitally. These are also known as digital 
clinical thermometers and run on batteries. These measure 
Then how do we 
find out how hot 
or cold a body 
is? 
Fig.7.2: A digital clinical thermometer
Tip
Chapter 7.indd   125 10-07-2024   12:50:49
 Curiosity | Textbook of Science| Grade 6
126
Do you 
know?
Earlier, mercury thermometers were used for measuring 
the body temperature. But mercury is an extremely toxic 
substance and is difficult to dispose of if the thermometer 
breaks accidently. 
Digital thermometers pose no such risk and also the 
numbers in its display are easier to read. Therefore, 
mercury thermometers are being replaced by digital 
thermometers. Temperature in a digital thermometer 
is determined with the help of heat sensors. 
temperature when the thermometer is placed in contact 
with a person’s body.
For measuring temperature, the clinical thermometers 
generally use a scale called the Celsius scale. On this 
scale, the unit of temperature is degree Celsius and is 
denoted by °C.  
They are non-contact thermometers, 
also called infrared 
thermometers. Such 
thermometers can 
measure temperature 
without touching a 
person’s body and 
thus reduce the risk of 
spreading disease.
During the COVID-19 
pandemic, some special 
thermometers were used, 
which could measure the 
temperature of a person 
from a distance. What were 
those?
Chapter 7.indd   126 10-07-2024   12:50:58
Temperature and its Measurement
127
Activity 7.2: Let us measure
Let us now use a digital clinical thermometer 
to measure body temperature. You may 
measure your own temperature as well as 
the temperature of some of your friends. 
Talk to your friends to find out who would 
be willing to get their body temperatures 
measured by you.
 ? Wash your hands and the tip of the 
digital thermometer with soap and 
water.
 ? Reset the thermometer by pressing the 
reset button. 
 ? Place the thermometer under the 
tongue and close your mouth. 
 ? Wait till the thermometer makes a 
beeping sound or flashes a light.
 ? Take it out from the mouth and read 
the temperature on the digital display. 
 ? Record the temperature in Table 7.1.
 ? Clean the tip of the thermometer with soap and water, 
and dry it.
 ? Repeat the above steps for measuring the temperatures 
of your friends. 
Table 7.1: Body temperatures of 10 persons
Precautions  
to be taken while  
using a digital clinical 
thermometer
• To be used after reading the 
instruction manual of the 
thermometer. 
• Tip of the thermometer to 
be washed with soap and 
water before and after use.
• While washing, care to be 
taken to keep the digital 
portion such as the display 
out of water.  
• Do not hold the thermometer 
by the tip.  
S. no. Name Temperature (°C)
1
.
.
.
.
10
Chapter 7.indd   127 10-07-2024   12:50:59