Under the weather

If an English-speaking friend tells you that he is under the weather, does it mean that he is standing under the sky ? At that moment, is the weather rainy, sunny or windy ? 

I don’t want to play football with you this morning. I’m feeling a bit under the weather. 

“Under the weather”is a popular idiom which describes someone who is feeling unwell or in low spirits. 

It is hard to complete a big project on time when you are under the weather. 

The written form of the expression appeared as early as 1827 in an American publication. 

Scholars believe that this maritime expression comes from the sea rather than from the sky. Many years ago, when a sailor was feeling sick, he would be sent to stay below the deck to protect himself from the weather. 

Similarly, in the past, people had to travel on ships for many days if they wanted to go to a faraway place. It was very easy to become seasick on the high seas when the weather was bad. They would be told to go down to the cabins in order to relieve the symptoms. 

Nowadays, what can people do when they are under the weather （不舒服；精神不好）on a ship? Doctors advise that passengers should sit in the middle of the boat, look straight ahead at the horizon, or try some ginger sweets and ginger tea. They should not read or use electronic gadgets. They should also avoid eating heavy meals before or during travel.