It is better to time your cycling ride at a shady time of the day like early morning or late afternoon if possible. This will reduce the amount of sweating due to high temperature and prevent dehydration. Taking small breaks during cycling also helps keep hydration. Of course all this is possible when you have time on your hands. Wrapping a wet scarf over your head also helps reduce the sweat and water discharge.
Before you hop on to your bike, drink at least two glasses of water two hours before your plan. The water will get into your system and rejuvenate it. Fill your water bottle and place it on a carrier. If the weather is hot, fill it with cold water. To keep the water cool for long, wrap it in a wet cloth will help keep the temperature down.
An electrolyte drink can help you maintain hydration. Buy an electrolyte drink in powder or juice form. Mix the powder form in water and make an electrolyte solution. Make the electrolyte according to the manufacturer's instructions provided on the sachet. Fill your water bottle with it and add ice to keep it cool. Take sips before riding and during it to keep the water and mineral level constant in your body. Take a sip of your water or electrolyte solution after every fifteen to twenty minutes to keep the body hydrated. Do not wait to get thirsty because once you get thirsty, it means your body has already started to get dehydrated.