Few things are more refreshing than a true Hawaiian shave ice, something you need to enjoy in Hawaii as it is impossible to find an authentic version on the mainland. But they are close approximations, versions that will help you endure a heat wave, even as they leave you longing to be transported to Honolulu or Hilo. Fans of shave ice include President Obama, which is not at all surprising given his childhood on Oahu. To see our President and his family enjoying shave ice, click here.

True shave ice is fluffy, not crunchy, as a snow cone is.

Shave ice is made by shaving a solid block of ice and topping it with syrup. The best versions resemble an emulsion, with the syrup evenly distributed through and suspended in the fluffy ice. Although shave ice is similar to a snow cone they are more like second or third cousins that siblings. Snow cones are made with crushed ice and no matter how finely crushed the ice is, it is crunchy, not fluffy, and it does not absorb the syrup in the way that shaved ice does. A snow cone–or a shave ice made with crushed ice–will give you a brain freeze must more quickly and frequently than a true shave ice.

But what are you going to do when it’s blisteringly hot and you’re not headed to the islands? One option is Petaluma’s Snack Shack, located at 128 Kentucky St., where it is wedged between the Hideaway bar and Stink, a hip clothing store, near Sonoma Cutlery and Copperfield’s Books.

Petaluma's Snack Shack is just a few step east of the breezeway between Petaluma Blvd. South and Kentucky St.

On my way to the Petaluma farmers market on Saturday, I stopped by for a hot dog–absolutely traditional and good, with chopped onions, sauerkraut and relish offered on a tiny ledge inside the diminutive shop–and a root beer shave ice, my favorite. It was made with crushed ice cubes but the syrup stayed evenly distributed until the last bite. It was good.

Snack Shack offers more than a dozen flavors of shave ice, along with Italian sodas, frozen yogurt, vegetarian hot dogs and other snacks. And you can have a shave ice with frozen yogurt in the middle if you like, as well, which inches it a bit closer to the classic Malaysian dessert,

Malaysian ABC, which stands for "Air Batu Campur" and means "mixed ice." It is ubiquitous throughout Malaysia.

Ais kacang–almost always called ABC– is made with shaved ice topped with sweet red bean sauce, condensed milk, fruit syrups and all manner of other toppings, including creamed corn and colorful gelatinous squiggles that look like worms. If you visit Malaysia, it is impossible not to eat at least one ABC, as inevitably someone will ask you about it and when they learn you haven’t had one, they’ll drag you to a hawker stand or cafe.

The best shave ice I’ve had–so far–was at a tiny cafe at Hilo Tropical Gardens (1477 Kalanianaole Ave.) up the road from the Edith Kanaka’ole Foundation in Hilo. Hilo Bay Sugar Shack, located at 330 Kamehameha Ave., a short walk from the Hilo Farmers Market, is really good, too.