I have an Elite Deboyo that I use in winter so that I can have a nice drink of hot sweet tea when the temperature outdoors is hovering around freezing. It stores 550ml in the size of a regular 750ml bottle
Insulated water bottles in the summer are a waste of space. If you do the math, drinking a litre of water that is at 273K compared to 303K is going to make less than half a degree difference in temperature for my whole body mass.
Quantity beats temperature, because evaporation of sweat is how humans keep cool.
Latent heat of water 4.2J/g/C
Latent heat of vaporisation 2146J/g