It definitely keeps things hit or cold for more than enough time. I loaded it with ice and water, let it sit in my truck all day when it was 87 out and it still had half the ice left when I got out of work. It definitely has a solid leakproof twisting seel that works great. The only flaw is how wide the base of it is. You really gotta jam it down to get it in the cup holder. It actually doesn't even fit in the one in my wife's mini van