Not exactly the same but when Izzy had a cold we used a vaporiser in her room, and we also raised her cot slightly up one end (she was only about 4 mths old) so that her runny nose could run down and out rather than back down her throat...It all definately helped - also one thing I would do too is keep his room warmish.... really cold air (if it's relevant where you are!) can make it worse so a small space heater or keeping your house heating on can help overnight too.