Sometimes it gets so cold here in Ohio, it hurts to breathe. But people in South Korea are having trouble breathing outside because of another factor - dangerous yellow dust.
This is what South Korea's capital city of Seoul, looked like earlier this week. Meteorologists say it's the worst yellow dust storm in five years.
The storm is the result of a dust storm that started in China and Mongolia, and picked up some toxins along the way as it moved into the Korean peninsula.
Children, the elderly, and people who are sick have been warned to stay indoors, but even healthy adults are being encouraged to stay inside because the yellow dust can be bad for your health.
Lots of people are wearing face masks and eyewear to protect them when they do have to go outside.