Hydration
Water is one of the most important bodily resources to manage and if you are not careful where you top up it can be one of the quickest ways to die in your new world. Drinking water is as simple as right clicking water with an empty hand or drinking from a glass bottle but be very careful that the water you choose to consume is clean. There are 4 types of water found in the Minecraft world:
Cold: Found in biomes with low temperature or crafted with a snowball and a clean bottle of water. Useful for cooling you down after a hot day but don't over do it and give yourself the chills.
Dirty: Found in swamps, jungles and discoloured water or crafted with dirt and a clean water bottle. Can make you sick for a short while and sometimes even poison you. Drink at your own risk.
Salty: Found in oceans, beaches or crafted with sand and a clean water bottle. Drinking this will make your hydration drop faster afterwards, the more you consume the faster you die!
Clean: Drink as much as you like, no side effects to be found here.
Any unclean water bottles can normally be distilled by boiling them in a furnace so if you can't find any naturally clean water nearby the get a furnace as soon as possible. An alternative method of obtaining clean drinking water is to place fire/lava underneath a cauldron, this will make any water inside it clean for direct consumption or filling bottles.
(main article: Camel Pack)
Now if you need a more convenient source of water while traveling and don't want to carry so many bottles (or a bucket of water to place and drink from) then the Camel Pack is for you.
This piece of equipment is vital for long mining trips or exploration where temperatures are high and inventory space is precious. This little backpack can be filled in a crafting table with 4 bottles worth of water and automatically fills 1% hydration every second when worn in the chest armor slot and if you feel like sharing the filling process can be reversed to fill bottles with clean water.
If you're hydration drops below 10% then the player will become heavily fatigued hindering any last minute attempts to find water. Try not to let your hydration drop to this level, people usually resort to drinking salt water at this point if it's the only water available however this is not a good idea unless you can find a clean water source faster than the rapid dehydration it causes can kill you.
If your hydration reaches 0%, you will of course start taking heavy damage and ultimately die within seconds.