science experiment....insulating cold water bottles?

well this might not help but I know for a fact that the sun is mostly attracted to DARK and DULL objects so dont insulate the bottle with anything that is a dark color (e.g. navy or black). go for whites etc.

are you allowed to use cotton? it might work...

Basically you want to use things that trap air. The trapped air will help insulate it. So the suggestions for newspaper (if it's crumpled), foam, cotton, etc. are good. I wouldn't use salt. And wrap it all in tin foil. That reflects away heat radiation that would try to get into the bottle.

It won't truly harm something, besides the shown fact that this is not any longer a stable theory in the previous 4 months. toddler's tummy is so small that she desires each little bit of "tummy actual property" to take interior the food from breastmilk or formula. Giving a new child water basically takes up powerful tummy area this is mandatory for milk and might sell weight-loss and undesirable well-being. further, the water lined in breastmilk or formula is all the liquid toddler desires. whether this is warm outdoors, she'll get adequate from this.

popcorn, styrofoam, foam rubber, etc.

aluminum foil on outside to reflect sun

another way is to wrap it in wet cloth--the evaporation will help cool it.