Make sure he sleeps slightly propped up too. he could have a nasal drip - I had this a while back and the nasty stuff drips from the back of your nose and settles on your chest. (even tho you may not have a runny nose or even a blocked nose, it's still there - lurking)
A good nasal spray should help too.
If he.s got phlegm on his chest too, he could use an expectorant cough medicine. If its just in his throat he could take cattarh pastilles {boots) which may help. The other produst i know of that will definately help is boots bronchial mix (it absolutly stinks but it works wonders) also steam inhalation with menthol chrystals. Lastly dairy products can make nasal drip worse!!!
steam inhilation with Vicks vapour rub, put a dollop in boiling water in a basin, put towel over head and breath in the vapour.
Is there not a "walk in" clinic near you ? otherwise go to your nearest A &E.
If it's really bad he might need to get a course of antibiotics such as amoxycilin but only if the infection has reached his chest and taken over it completely. Usually if one lung is infected, by beating each side of his chest you will notice that one lung has a deeper sound, the doc will probably do this with his stethiscope whilst asking him to take deep breaths and prescribe antibiotics but these should only be taken as a last resort as they deplete your immune system.