cold definitely tastes much less than room temp. also, age of your child is a huge factor here. toddler – lay them on their back across you lap, pinch mouth open squeeze in and quickly follow with blowing in after it. Learnt it in a peds er. Works everytime. For an older child have a forbidden treat on hand – piece of chocolate, cup of soda, etc. to be given after the meds.
Good luck and refuah shelaimah! A kid would have to be at least 8 or 9 for the “its good for you” argument to carry any weight.