With the blistering summer temperatures we are having, most people just stay at home and escape the heat by using their air conditioners. There may not seem to be many ways to keep cool other than going to a mall or driving to the nearest beach on a weekend. Almost all city residents have their own tricks to cool off, but this list of activities can help anyone in Istanbul beat the heat and enjoy their time in this season.Horse-drawn carriagesIn summer, people take the ferry early in the morning to the Princes' Islands, commonly referred to as the Adalar in Turkish. Just off the city's Asian side and composed of nine islands - four major and five minor - the Princes' Islands gives visitors the opportunity to ride in a horse-drawn carriage and tour the islands without walking under the hot sun. As private motor vehicles are not allowed on the islands hourly tours in the carriages are available throughout the week. It is quite enjoyable to see the islands' old mansions, pine forests and palm trees while riding along the coast and experiencing a 19th-century bourgeoisie ambience. After breakfast, a morning tour is the best thing to do on the largest island, Büyükada, with family members and especially with children. On Büyükada, certain horse-drawn carriages also offer a daily program with lunch at a fish restaurant.Drink iced coffeeIt is understandable that a morning cup of coffee or a mid-afternoon caffeine boost with espresso are not easy to leave, but your favorite pick-me-up drinks are unfortunately not useful in the hot weather. This is a good time to check iced coffee recipes on Google and try them at home, or to just have a good iced coffee to go at a favorite cafe.For homemade iced coffee, here is a recipe: Take a pound of ground coffee. Pour eight cups of cool water over it. Stir until the water saturates the coffee. Cover the container and wait for at least eight hours. Then take a coffee filter and slowly pour the steeped coffee through it. Dilute with milk and serve over ice. Adding a flavor like caramel or whipping cream on top upgrades the taste. Some of best destinations for iced coffee in Istanbul are The House Cafe in Nişantaşı, Federal Coffee in Galata, Cafe Wien in Şişli and Walter's Coffee Roastery in Caferağa.Fancy some sorbet?For those who love ice cream recipes, sorbets can be a great option. Sorbets are made of simple syrup (water and sugar) and have flavorings. They generally do not contain any dairy products, and the challenge is to keep down the size of the ice crystals. It is easier to make sorbet compared to ice cream. In Bostancı, a neighborhood in the city's Asian side, Yaşar Usta Sorbet & Ice Cream is an iconic spot for both sorbets and ice cream. Yaşar Usta's sorbets are made of seasonal fruits, and customers can choose among a rich variety including strawberry, lemon and raspberry or chocolate. My go-to sorbet flavors here are chestnut, watermelon and banana.Rooftop poolsDoubleTree Hotel in ModaThis may be a more luxurious option, but rooftop pools are a good way to cool off in Istanbul. Although they are not many of these types of pools here, three locations in the city - Wyndham Istanbul Kalamış Marina, the Marmara Taksim and DoubleTree by Hilton Istanbul - have rooftop options open all throughout the summer. A view of the Marmara Sea is seen from the Wyndham Istanbul's pool, and refreshing swimming accompanied with a special pool menu is available at the Marmara Taksim. The third option is in Moda, so Hilton's terrace pool is perfect as a weekend activity for residents on the Asian side.Go undergroundSeriously! The city's underground spots, such as the most famous one - the Basilica Cistern in Sultanahmet - are worth a try if you want to spend time somewhere cool. An eerie mosque - Yeraltı Cami - in Karaköy occupies a crypt belonging to what was called Castellion, or the Castle of Galata, built at the end of the 6th century by Tiberius II to control the Golden Horn. Yeraltı Camii literally means Underground Mosque. What remained of the ruins was converted into the present day mosque. There are two tombs of martyrs, both of whom are believed to have died in the first Arab siege of the city in the 7th century. Among some locals, the mosque is also called "Kurşunlu Mahzen Camii."