Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that your baby has got a viral infection leading to the symptoms of 
cold, congestion and 
fever..
As he is just 7 months old I would not recommend you to give him any 
cough and cold medicines and you can simply follow the following remedies for relieving the symptoms..
You can put saline nasal drops in his nostrils that will loosen the mucous and ease in 
drainage..
You can use a cotton swab to gently remove mucous that is plugging the nostrils..
Feed him with plenty of fluids..
Use a cool mist humidifier in his room..
Steam inhalations from a steamer can help her in easing breathing..
You can do warm compresses over the chest, take care it should be just warm and not hot at all..
In case if still it does not improve consult a Paediatrician and he can advise infant doses of 
dextromethorphan for cough suppression and Pseudoephadrine for congestion but should not give without consulting a Paediatrician although it can be given to infants above 6 months and as your daughter is 7 months it can be given only under medical expert's supervision..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.