Other results showed, most Brits wake with common signs of dehydration - dry mouth (65%), thirst (70%), fatigue (54%) and headaches (29%). We wake up at our most dehydrated, yet many of us reach straight for caffeine. Pro tip: Leave a glass of water on your bedside table so it’s the first thing you reach for. Think Smarter HydrationHydration isn’t just about water – electrolytes like sodium, potassium, and magnesium help your body retain and use fluids effectively. If you’re active or sweating heavily, consider adding an electrolyte powder sachet to your glass of water or water bottle.