This Texas summer has been a scorcher, and it feels like there’s really no foreseeable end in sight for these triple-digit-temperatures. It’s important to stay cool and hydrated to avoid fatigue during this heat, but did you know there’s more to hydration than just drinking water? Water is essential to life, but it is not the most hydrating beverage.

The hydration strength of certain drinks is measured by the hydration index; “The hydration index is modeled after the well-known glycemic index, which measures how the body responds to the carbohydrate content of different foods. (The glycemic index is used to help individuals keep their glucose-insulin response under control.) The guiding principle behind the new hydration index is that some fluids last longer in your body than others, providing more hydration.” (Source: New York Times)

Read on for recommendations on what beverages to keep by your side this summer:

Best: Milk

Milk is composed of mostly water, but is naturally high in nutrients and electrolytes like sodium and potassium. Milk is held in the stomach long enough to process all of the nutrients it contains, postponing dehydration. Water exits the body more quickly and dramatically, making milk the better choice.

Better: Water

The Mayo Clinic recommends about 15.5 cups (3.7 liters) of fluids for men and about 11.5 cups (2.7 liters) of fluids a day for women. These fluids can come from many different sources like sparkling water or unsweetened tea, as long as no sugar is added. This recommendation should also be adjusted based on your lifestyle, activity level, and medical needs.

Encouraging kids to drink water may prove to be a difficult task; sneak more fluids into their diet by diluting sugary natural fruit juices or offering popsicles as a source of hydration.

Good: Tea and Coffee

Caffeine in tea and coffee can act as a diuretic, but it’s primarily the sugar content found in most tea and coffee drinks that forces these beverages into the ‘less hydrating’ category. However, lower-sugar drinks such as Yaupon (Shop: Texana Tea) or making your own tea from caffeine-free ingredients is recommended.