Create another empty view in viewMain called viewHover and position it where you want the hover views to show. Then in IB add either viewHot or viewCold (not both) as a subview of viewHover.
Then call a method like this to flip the views:
-(void)flipViews
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1.0];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:viewHover cache:YES];
if ([viewHot superview])
{
[viewHot removeFromSuperview];
[viewHover addSubview:viewCold];
[viewHover sendSubviewToBack:viewHot];
}
else
{
[viewCold removeFromSuperview];
[viewHover addSubview:viewHot];
[viewHover sendSubviewToBack:viewCold];
}
[UIView commitAnimations];
}