Physicians have proposed that when you’re upside down, your liver and intestines put extra weight onto your lungs, making it harder to breathe.

医生提出，当你倒立时，你的肝脏和肠道会给你的肺部增加额外的重量， 使呼吸更困难。

Wildfire smoke and ash can irritate eyes, nose, throat and lungs, making people cough or wheeze and can make it hard to breathe, according to the US Centers for Disease Control and Prevention (CDC).

据美国疾控中心称，山火烟尘和灰烬会刺激眼睛、鼻子、喉咙和肺部，使人咳嗽或喘息，并使呼吸困难。