Thanks to everyone who replied to this message.

I have got a sleeping bag for him but i didn't think it was cold enough for him yet and i'm scared of over heating him.

The one i have seems to be a quite thick polar fleece one but i will try to find a slightly less heavy one when i go shopping.

Natalie thanks also for the tip of putting the sheets on side ways it might just do the trick if the sleeping bag doesn't work.

Thanks once again for all your answers to a first time mum all information given i find invaluable.