人教版必修5第五单元课文.doc

人教版必修5第五单元课文.doc必修 5 Unit 5 First aid-Reading
FIRST AID FOR BURNS
The skin is an essential part of your body and its largest organ. You have thr ee layers of skin which act as a barrier against disease, poisons and the sun's har mful rays. The functions of your skin are also very complex: it keeps you warm or cool; it prevents your body from losing too much water; it is where you feel cold, heat or pain and it gives you your sense of touch. So as you can imagine, if your skin gets burned it can be very serious. First aid is a very important first step in the treatment of bums.
Causes of burns
You can get bur ned by a variety of things: hot liquids, steam, fire, radiati on (b y being close to high heat or fire, etc), the sun, electricity or chemicals.
Types of burns
There are three types of burns. Burns are called first, second or third degree bur ns, depending on
which layers of the skin are burned.
◎ First degree burns These affect only the top layer of the skin. These burn s are not serious and should feel better within a day or two. Examples include mil d sunburn and burns caused by touching a hot pan, stove or iron for a mordent.
Second degree burns These affect both the top and the second layer of th e skin. These bums are serious and take a few weeks to heal. Examples in elude severe sun burn and bums caused by hot liquids.
Third degree bur ns These affect all three layers of