Question Author
lankeela - yes the two go together, but differ in intensity during 24 hours, that's why I wanted to know if one was WORSE for dogs than the other.
Vagus - I check the cloud cover and humidity every time I go outside, which is often. I need eyes in the back of my head, or else Rufus is clever and very solid. He's able to barge his way through my inefficient fence and escape. I wouldn't mind - since he comes back after a while - but his breed have no road sense and people round here find it necessary to drive at 50/60 mph on our road, which is very short, so there's no need for speed.
CrapAtCryptics - I bought a cooling jacket for £42. He wore it once. Ever since, if he sees it, he runs and hides under the bed. Frustrating to say the least!