It’s important to stay hydrated at all times and water management is key to a successful trip. Carrying water is good but can only last so long due to the weight the water containers add to your pack. You should know where sources of water, such as springs or creeks, are before you set out. Also, carrying a water filter is the key to avoiding sickness from contaminated water.
Keeping water warm in colder temperatures can be a challenge. You can keep a well-sealed container in your sleeping bag with you overnight to keep the ice at bay. Also, having a reliable stove will heat up the water when you need to.