1、（人教新版）五年级英语下册课外拓展Unit 6 Whats wrong with you?一、FeverFever is often a sign of infection or illness. Although it is believed that fever helps the body fight infections by stimulating natural defense mechanisms, fever can make a child uncomfortable and dehydrated. Because fever may point to underlying
2、illness, finding the cause of fever is the priority.Your child may have a fever if her temperature is: higher than 100.4 degrees Fahrenheit (38 degrees Celsius) measured rectally higher than 100 degrees Fahrenheit (37.8 degrees Celsius) measured orally higher than 99 degrees Fahrenheit (37.2 degrees
3、 Celsius) measured under the arm What Is Fever?Fever is when the bodys temperature is raised above its normal level. Most people think a normal temperature is about 98.6 degrees Fahrenheit (or about 37 degrees Celsius), but in reality, a persons temperature varies somewhat during the day. Typically,
4、 its slightly lower in the morning and slightly higher in the evening.Like most warm-blooded mammals, humans seem to operate best with a relatively constant internal temperature. The brains hypothalamus acts somewhat like a thermostat to regulate the bodys temperature. Fever occurs when the hypothal
5、amus is “set“ to a higher than normal temperature. This higher setting is usually due to the presence of small molecules, known as pyrogens, in the blood. Pyrogens can come from external substances such as bacteria, viruses, or toxins. Sometimes tumors and other substances created within the body ca
6、n release pyrogens.Under some circumstances, the bodys elevated temperature can help fight off an infection, but this isnt always the case. Excessive fever can cause problems such as dehydration and discomfort. Acetaminophen and other fever-reducing medications work by decreasing the levels of pyrog
7、ens at the hypothalamus.二、Who needs a Flu shotIf you had the flu last year, you know how bad it can make you feel. Youre hot one minute, cold the next, your head aches, and your energys gone. But some people never got the flu, also called influenza (say: in-floo-en-zuh), because they got a flu shot.
8、 Not everyone needs a flu shot, though. Read on to find out if you should get one.1. What is the flu shot?The flu shot is a vaccine (say: vac-seen) that protects against the influenza virus. Like other shots youve had, it helps your body fight infections. The flu shot contains a small amount of dead
9、, or killed, flu viruses. The flu shot wont give you the flu, but those dead viruses are enough to get your bodys immune system ready to fight off the real flu when it comes around this winter. 2. Who should get a flu shot?Almost anyone can get a flu shot, but most kids who are healthy dont need it
10、because even if they get the flu, theyll probably just be sick for a little while and then get better. But there are some kids who may get very sick if they catch the flu, so doctors recommend that these kids get the flu shot. Kids who have asthma or other lung problems, heart problems, kidney disea
11、se, diabetes, HIV, or sickle cell anemia should get a flu shot every year. If you have one of these or some other medical problem, you might want to ask your parent to call the doctor about getting a flu shot. Another reason to get a flu shot is to protect someone in your family who might get very s
12、ick if that person caught the flu. The idea is this: if you dont get the flu, you cant spread it to anyone else. If you live with someone who has any of the medical problems listed above and you get the flu, that person could get very sick. Older people should get flu shots because their immune syst
13、ems (the bodys disease-fighting system) arent as strong as yours. So if you live with your grandparents, getting a flu shot will help to protect them.Babies and little kids can get very sick from the flu, and doctors encourage parents to have their kids who are between 6 months and 2 years old get f
14、lu shots. Babies younger than 6 months old also could get very sick from the flu, but they are too young for a flu shot. So if you have a new brother or sister or if your mom is going to have a baby soon, you and your family might want to get flu shots to prevent her and the new baby from getting sick.
