It's not for a T-shirt, but it's warm for a jacket? Just have a Loap URYLON vest at hand and the problem is over. It fits in the pocket of any backpack and reliably protects the body from unexpected cold winds and cold. The vest is made of light and breathable TECNOSOFT material, which at the same time reliably protects against the wind. In addition, the vest is insulated in the chest part, the loins always remain covered thanks to the slightly elongated back. Do you suffer from frequent sore throat or blockage of the cervical spine? Practical stand-up collar keeps your neck warm and without blowing. The snug slim fit fits well on the body, for even more comfortable wearing, the material of the vest - as well as the bottom edge - is slightly elastic. Reflective elements are a very practical accessory, and two closable pockets will also come in handy. The Loap URYLON vest is available in sizes S-XXL and more colors. Wash at 30 °C without fabric softener. Lightweight, breathable, windproof material. Snug fit on the body. Insulation in the thoracic part. Slightly elongated back. Elasticated hem. Practical stand-up collar. Reverse zipper with chin cover. 2 zipped pockets. Reflective elements. In sizes S-XXL. Intended for: hiking, leisure, camping.