带外套吧。

You can use this phrase as a standalone sentence. Just say it as you see someone heading for the door. You can also add a reason before it. For example, mention it is raining or the office is freezing. It works perfectly in person or over a quick text message. No complex grammar is needed here. Just the verb, the noun, and that friendly particle.

Use it when the weather forecast looks unpredictable. It is great for evening plans when the temperature drops. Use it if you are going to a mall or cinema. Chinese indoor spaces often have very strong air conditioning. It is a standard phrase among friends, family, and even colleagues. It shows you are observant and considerate of their well-being.

Do not use it in a high-stakes formal presentation. It is too casual for a speech to a large audience. Avoid it if the person is already wearing a heavy coat. That would just be confusing! Also, if you are at a black-tie event, specify the type of clothing. 外套 is a general term for a jacket or coat. Don't use it if you are trying to be extremely demanding. The 吧 makes it too polite for an angry command.

In Chinese culture, caring for someone's physical health is a love language. Asking if someone has eaten or telling them to dress warmly is common. It is not seen as bossy or intrusive. Instead, it is a sign of intimacy and protection. Mothers are famous for saying this constantly. Even young friends use it to show they value each other's health. It reflects a collective culture that prioritizes mutual care.

You might hear 记得带外套 which means "remember to bring a jacket." Another version is 外面冷，带件外套吧. This adds "it's cold outside" for extra context. If you want to be more specific, you can say 带件薄外套 for a light jacket. Adding the measure word 件 makes the sentence sound more natural and rhythmic. These variations all carry the same spirit of kindness.