my bitch had 3 pups last one 5 hours ago, she is still panting ( its quite a warm evening) is this normal ?

In a word, yes. The panting following whelping is usually caused by the discomfort of the uterus contracting, and often lasts for several days. Has the vet checked her over to make sure she has no more pups inside?

How is she doing today?

My bitch had her pups 2 days ago and is still panting constantly, just like when she was in labour, so like you I hope this is normal.  The vet checked her over yesterday and was happy with her, so hopefully all is ok, I guess this weather doesn't help. She has also been digging.

The after pains are painful (hence digging and panting) and also if the bitch is hot, as pups need heat.

I found with my girl that she enjoys lying on her back and me wiping her down with a cold damp flannel. This has really eased her panting and 2 days after labour and the panting is very intermittent now. I think they find this soothing and it cools down the teats that are roasting after milk production. I just dry off her belly before she goes back into feed. X

> I just dry off her belly before she goes back into feed. X

Sweet, but you'd never get one of mien out from their babies for at least the first three days.  Need to clip a lead on to make them go to the toilet.

By day 5 they will sometimes lie beside the whelping box when hot, but generally will stay in with the pups pretty much constantly until their eyes open, except for toilet breaks.

The pups need to be feeding almost constantly for the first three days to bring the milk in, so I don't encourage them to come out at all, feed in the whelping box, so they have no need except for the toilet breaks.

Brainless, pugs are prone to over heating and with the heat pad we have for the pups, and this weather it is too hot for my girl to stay there all the time, she just pants erratically. She has access to leave her whelping box but wont without encouragement so we lay her on the laminate next to the box so she can see pups and wipe her down. Pugs also aren't as good mothers as other breeds I believe, for a pug she is brilliant.

My other girl wouldnt leave the whelping box or even sleep until the pups were all content. Like you say coaxing her was a nightmare, she wanted to eat all her meals in the whelping box and toilet breaks were brief and frantic. She over heated during the 1st week of pregnancy and we had an emergency trip to the out of hours vets who advised in future of encouraging regular breaks away from pups even if for 5 minutes. But that was incredibly difficult as taking her away caused more distress so it was a catch 22 situation. The puppies are all doing really well so far touch wood.

What is your breed brainless, they sound lovely mothers xxx

Mine are Norwegian Elkhounds and the adults don't like heat, even the newborn pups don't like it any hotter than just over 20'C (I keep a thermoter on the whelping box). 

So I have a heat pad that is only about A4 size in a 3 foot square whelping box. 

This means it covers only the centre of the box and the bitch can avoid lying on it whichever side she lies.

In hot weather I only use shredded paper (keeps pups dry) as they kick the vetbed out.

You are right as a breed theya re usually good mothers, mostly more efficient than doting, though I have had two that have been really devoted Mums.