State the similarities and difference between laboratory thermometer and clinical thermometer.

Binny was suffering from fever. Doctor took her temperature with the clinical thermometer. Binny requested the doctor to show the thermometer and observed it carefully. Then she asked the question related to the construction of clinical thermometer. The doctor explained that it has a triangular stem on which markings are $35 °\mathrm{C}$ to $43 °\mathrm{C}$. It has a thin big bulb containing mercury which is connected to a very thin tube running inside the stem. This thin tube has a kink near the bulb. There was one marking to the stem, which was of red colour. Binny thanked the doctor for his good explanations.
Answer the following question based on above information:

What are the values shown by Binny?

Binny was suffering from fever. Doctor took her temperature with the clinical thermometer. Binny requested the doctor to show the thermometer and observed it carefully. Then she asked the question related to the construction of clinical thermometer. The doctor explained that it has a triangular stem on which markings are $35 °\mathrm{C}$ to $43 °\mathrm{C}$. It has a thin big bulb containing mercury which is connected to a very thin tube running inside the stem. This thin tube has a kink near the bulb. There was one marking to the stem, which was of red colour. Binny thanked the doctor for his good explanations. 
Answer the following question based on above information:

Why is the thermometer marked from $35 °\mathrm{C}$ to $43 °\mathrm{C}$?

Binny was suffering from fever. Doctor took her temperature with the clinical thermometer. Binny requested the doctor to show the thermometer and observed it carefully. Then she asked the question related to the construction of clinical thermometer. The doctor explained that it has a triangular stem on which markings are 35°C to 43°C. It has a thin big bulb containing mercury which is connected to a very thin tube running inside the stem. This thin tube has a kink near the bulb. There was one marking to the stem, which was of red colour. Binny thanked the doctor for his good explanations.
Answer the following question based on above information:

Why is it necessary to measure the temperature of a sick person?