I used these mugs every morning for my coffee and I often don't get to drink my whole cup right after I make it due to my 2 young kids. These mugs keep my coffee nice and hot even when I return to drinking it a good 45 minutes after it is made! I have also found that they are super durable since I wash them so much and the outside of the glass stays cool to the touch, so you don't even have to use the handles.