It's our first time flying tonight with our 3.5-month old, and somehow I could not find the answer to this by googling--if you try to bring those "nurser" bottles of ready-to-use formula through airport security, do they open them all up, or do they just recognize that it's a sealed bottle formula and leave you alone? I guess I could bring fresh breast milk already in bottles instead, I just don't want it to go bad while it sits out for hours while we are in transit.
Also, if your baby is particular about milk being warm, how did you deal with that during air travel? Ideally I'll try to just nurse, but want to have my bases covered just in case we need to do a quickie bottle fix.

Any other tips you have for little-baby air travel would be much appreciated Thanks!