In the summer heat, keeping hydrated is very important. Imagine that you go to your sink to fill up a glass, and the water coming out is lukewarm. How disappointing! There can be many different causes for this, depending on the type of system you have installed.
If your water cools down after running for a while, this indicates that it gets heated up on the way from the source to your tap.
You want to check that the hot and cold water pipes aren’t too close to each other, since there could be heat transfer. If that is the case, you can get insulation in between them to prevent it from happening.
It is also possible that your pipes run through an area where there is no insulation, or the insulation is insufficient. Depending on whether this is in an open area, such as a garage, or inside of the wall, this will dictate how much work is needed to make sure that your water stays cool all the way to the tap.