YETI Rambler Vacuum Insulated Cup & Standard Lid, 14-Ounce

Nothing can ruin a morning quite like taking a sip from your coffee mug only to discover that your beverage is unappetizingly lukewarm. Thankfully, there are tons of insulated cups on the market that are ready to rescue you from enduring such an experience. And there are loads of variations, from petite mugs that are perfect for camping to giant tumblers that are sure to quench your thirst throughout the workday.

In addition to keeping hot drinks warm and cold drinks chilled, insulated mugs are also designed to prevent spills. Some have sippable snap-seal lids, while others come with reusable straws made of plastic, rubber or metal.

Many cups that effectively maintain the temperature of hot and cold beverages have vacuum insulation, which relies on a vacuum (a space that has been emptied of air) to slow the spread of heat and cold.

Vacuum-insulated cups, which are typically made of metal or glass, have both an inner and outer wall that is separated by a thin layer of vacuum. The outer walls have a reflective coating to keep heat inside the inner chambers; meanwhile, convention (how heat rises and cold sinks — causing the loss of heat) is prevented by the cup’s lid.

That’s why vacuum-insulated mugs and thermoses are a great investment if you want to keep a cup of java hot for hours.

• A tumbler is a type of insulated cup that is commonly used to hold cold drinks (though many tumblers can accommodate hot beverages, too). The cups have no handle and come with a lid and straw, making them great for filling with ice water, smoothies and more.
• After frequent use, your insulated mug may develop stains, particularly if you use it to drink coffee or tea. Remove the stains by rinsing your mug with a solution of distilled white vinegar (1/2 cup), baking soda (1 teaspoon) and dish soap (a few drops). Be sure to rinse the cup with warm or hot water and dry it thoroughly afterward.
• Don’t put your insulated mug in the dishwasher unless the manufacturer’s instructions tell you to do so.
• Insulated cups aren’t typically microwave-safe.