An arm warmer is a piece of clothing that goes on your arm to help keep you warm. It's like a sleeve that you wear over your arm, kind of like a sweater but just for your arm. Arm warmers are often made of soft materials like fleece or wool to help keep you cozy.
Sometimes, when it's chilly outside but not cold enough to wear a big jacket or sweater, arm warmers can be really helpful. They help keep your arms from getting too chilly without making you hot and sweaty like a big coat might.
Arm warmers can be really useful for people who do outdoor activities like running, biking or hiking. They can be easily taken off or put back on if you get too hot or too cold, and they can also help protect your arms from things like the sun, wind or rain.
Overall, arm warmers are a simple and practical way to keep your arms warm and comfortable, whether you're out exploring in the great outdoors or just chilling at home.