This vest has been an absolute game changer for my medical alert dog. It's already reaching temperatures of nearly 100° in our area and my job requires us to be out and about during the hottest part of the day, so I turned to ruffwear for a solution. The vest is very well made and fits perfectly under both her load up harness and her service dog vest. She stays cool for hours and it is very easy to "recharge" when necessary.