We all know that water’s important for us. Up to 60 per cent of adult bodies are water, and we’re always told to drink lots of it to make sure we stay hydrated. But why is it extra important for us to drink more water in the summer, and how does drinking water help us in the hotter months? Water is always critical for our health, but here are 3 reasons you need more of it in the summer heat: Hot weather, extra physical activity, and spending more time outdoors.