It's far too hot out there to justify wearing a long sleeved base (the term 'boil in a bag' comes to mind), so perhaps something a little less bulky? A sleeveless base contains all the qualities you need for warm weather riding. They work to draw moisture away from the skin, so you can stay dry and your jersey can perform more effectively.
They're generally made from highly breathable, moisture wicking materials. Merino wool, known for its temperature and pong-control, and lightweight mesh fabrics, are both commonly used to provide the cyclist with exceptional comfort.
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