I love to keep my coffee hot in the mornings and my ice water cold in the afternoons.  This mug is fabulous for doing both!  I make my coffee at home in the morning before going to work, and when I get to the office it is still piping hot and ready to drink.  After I am finished with my coffee, I do a quick rinse and fill it up with ice water.  Throughout the day I am constantly sipping on my icy cold beverage and it stays that way until it's time to refill it again.  This is just a great all-around daily use beverage container!