We also tested two devices purported to use light and/or heat to treat acne. The makers of the Zeno Hot Spot ($40 for 80 uses) and the rechargeable No!No!Skin ($180) claim these devices will ...

5. Heat Rash Heat rash, or miliaria, develops when your sweat glands and ducts become clogged. That blockage causes sweat to build up, which brings about small pimple-looking bumps on the skin.

Elevated ambient temperatures and humidity levels enhance sweat gland activity resulting in excessive sweating, which can clog pores to cause or exacerbate acne or pimple breakouts. To prevent ...