Im gald some of you still put the cooled down bottles in the fridge as that is what I have been doing!

I have a microwave steroliser so I then boil kettle and fill up bottles and leave on sifde to cool and pop into fridge for when I need them. Then I take off teet and put bottle in microwave for 40 seconds and put my scoops of powdered milk in, shake and give.
Is this ok? The reason I ask is that lately the milk is not coing out the teet but I dont put them in microwave! Isabelle has been getting bad colic too which makes me wonder if its the teets?! She also hasnt pooed for 2 days and gets bad wind!