4. Stainless Travel Mug
running late for work; nothing better than carrying your travel mug. Oh wait, the coffee brewed hours before is just cold and tasteless. What now? Brew it again or just microwave it for a minute. And that’s where the hurdle is. Heating up liquid in this container is basically pointless. The metal body of the mug will restrain the heat from warming the liquid. Furthermore, it can cause damage to your microwave. So refrain yourself from putting such containers into the oven for the sake of saving time and hassle.