Your friend has written an email that he has had a bad cold.write a reply (50-60 words) an ask how he / she feels and give him some advice: to have a rest.to go to bed.to see a doctor.

Hi, John.
I have read your letter and it is very good that you have written to me about this problem. I think that I can give you some advice.
First of all, you should check your body temperature, if it is normal, just drink some tea and go to bed. If the temperature is high, take some pills, which lower the temperature. You should drink very much water/tea and lay in the bed. If nothing helps you, you will have to see a doctor very soon.
I hope that everything will be allright. Reply me, as soon as you can, how are you.
Best regards
Brad