vinyl swimming pool covers run on a tracks beside your pool so are very easy to remove and put on. The vinyl does keep some heat in the pool if you put the cover on after swimming, but water holds heat pretty well in the first place so it won't make too much of a difference. These covers are great for keeping debris out of the pool. You will see in the next cover I talk about why I'm a fan of the non porous vinyl. The only downside is if you have any shrubbery or built up rock features around the pool, theses covers don't work.