In winter, the weather is very cold. Some people feel ill in the winter. If you don't wear warm clothes, you will have a cold. How do you feel if you have a cold? You will be very tired. Your head may hurt badly. Your temperature (体温) will be higher than 37. Then you may have a fever (发烧). But don't worry! If you are ill, see a doctor. You should take some medicine (药) and stay in bed for a few days. And you should drink more hot water. Then you will feel better soon.