There are a ton of quick and cheap electrolyte drink recipes that you can find online. Tea, coffee, cocount water, milk, milk substitutes, juice, etc are all hydrating despite extremely persistent myths. Many fruits and veggies like cucumbers, watermelon, strawberries, bell peppers, etc have high water content and are a great way to hydrate while also getting vital nutrients. Popsicles are also a good way to stay cool and hydrated and you can buy them or make your own with whatever ingredients you want; there are recipes online, including ones for electrolyte popsicles, but you can also just do basic ones with your choice of fruit juice and whatever you want to add, like chunks of fresh or frozen fruit.