You know those frozen blueberries you keep for smoothies? Your dog thinks they are little chilly jewels from heaven. Toss a handful into their bowl right before bed.
Or, go full mad scientist: fill a Kong with plain yogurt, a few blueberries, and some pumpkin puree. Stick it in the freezer for an hour. When you give it to them at bedtime, they’ll be so busy licking that brain freeze they won't even think about the heat.
Pro tip: Do this outside or in the kitchen. The slobber factor increases tenfold when it’s frozen. You’ve been warned.