Now that it’s summer time and you’ll be (hopefully) spending some time outside under the hot sun, it’s extra vital that you get enough water. While the push to drink more water has made its way into mainstream media and lots of people routinely carry water bottles with them everywhere they go, you may not know all the reasons – and benefits – of drinking lots of water.

Think back to biology (or your EMT course) – our bodies are made up of about 60% water. That means this delicate balance of fluids needs to stay at the right level in order for the body to work efficiently. When the fluid balance is tipped too low, that results in dehydration – a sign of the body not working efficiently. Your brain triggers your thirst when your body sends signals that it’s low on fluids, so it’s important to pay attention if you feel thirsty – the best thing to drink in that case is plain old water. While beverages containing water are more helpful than drinking nothing at all, plain water is the best for thirst.

Dehydration has many symptoms, and it can even affect your ability to concentrate, memory, and motor skills. Not only that, dehydration may make you moody. According to Mayo Clinic, a few early signs of dehydration include sleepiness or tiredness, dry and sticky mouth, headache, constipation (there’s no fluid to keep things moving!), and dizziness/lightheadedness. If you still don’t grab a drink after those symptoms show up, things get worse – extreme thirst, little or no urination, sunken eyes, shriveled and dry skin, hypotension, tachycardia, fever, or even delirium or passing out.

It’s important to remember that thirst isn’t always a reliable indicator of how dehydrated you are – children and older adults may not recognize the feeling of thirst. For them, urine appearance is the best indicator of how well-hydrated they are – the more the urine looks like water, the better hydrated they are. This also means the kidneys are working efficiently and ridding the body of toxins.

It’s especially important to load up on water if you’re exercising, since water helps your muscles keep from getting fatigued. If the cells in muscle tissue aren’t maintaining their fluid balance, the muscle won’t be able to work as hard, so you won’t be able to exercise as hard or as long. Add in the hot outdoor summer weather, and it’s a recipe for disaster if you haven’t been drinking enough water. It’s important to keep hydrated before, during, and after every workout.

Water even helps your skin – the water in your skin helps to form a protective barrier that prevents fluid loss. While drinking tons and tons of water won’t get rid of wrinkles, being dehydrated causes wrinkles and dryness. Anyone who is “glowing” is probably drinking enough water.

So now that you’ve got plenty of reasons to drink water, how much should you be drinking? Well, there’s not one answer that will fit every adult. It doesn’t hurt to go by the old 8 x 8 rule of 8, 8 oz glasses of water a day. At a minimum, you should be getting 4 cups of water a day. If you’re exercising, you’ll probably be drinking at least 10 glasses a day to get through your workout and replenish your lost fluid (sweat) afterwards.

The best way to decide your water intake is to just drink whenever you feel a little thirsty. Have a glass of water every time you eat, keep water by you whenever you’re sitting for a long period of time to sip on periodically, and make sure you drink after any sort of physical activity that could tire out your body (the water will also re-energize you!). In the summer, you’ll need to drink more water since the heat will cause your body to release more fluid. In the winter, you may find you need to drink more water to keep your skin hydrated from the indoor heat. If you’re sick, you should be drinking plenty of water to keep flushing out your system. Pregnant and breast-feeding women should make sure they’re getting at least 10 cups of water per day.

Now might be the time to invest in a water bottle to stash in your bag or car or anywhere useful for you remind yourself to drink water. Enjoy the warm weather and remember to drink (water) responsibly!