40oz Iron Flask with straw lid combined with liquidIV changed my life. I fly out of KAPA in summer and lose an insane amount of water in the cockpit heat. I've finished an entire 40oz after 90 minutes on one very hot day. There aren't affiliate links. I only use one sachet of Liquid IV in the 40 oz bottle or it's too sweet for me. IMO it adds just the right amount of electrolytes and flavor. But it's that straw that is a game changer because you can drink from the bottle vertically while flying and you can suck down a whole lot in a few seconds if you're busy in the cockpit.

https://www.amazon.com/dp/B07N2NC7WJ?psc=1&ref=ppx_yo2ov_dt_b_product_details

https://www.amazon.com/Liquid-I-V-Multiplier-Electrolyte-Supplement/dp/B07HCNM7KQ/