Cat on a hot garage roof?

Yesterday I arrived by train to keep JustSally company whilst she is recovering. Today we did some spring cleaning in the garden whilst Coco the cat watched down from the roof of the garage and then the roof of the house . But when it came to getting of the roof, she found it wasn't as easy as getting up there. We have just been for a walk along a nearby road with large houses on. As we walked along we rated the gardens and talked about what we liked about each house.