I’m not referring to alcohol.
The summer blazes. Florida’s red tide pricks at skin and distends nostrils, California forest fires clog lungs, humid urban inversions break your breath.  Wet bulb temperatures of 35 degrees celsius prove fatal to undressed humans after several hours.  One internet calculator puts 95 degrees Fahrenheit  with 80% humidity as providing a warning wet bulb reading of 34 celsius.
It’s time to drink.
As a doctor who sees many taking drugs that change people’s ability to sweat, like antidepressants, antipsychotics, antihypertensives and the like, it becomes more important than ever that people get enough water into them to survive the summer, every day and through many ways.
Reasons to Hydrate
The climate is changing.  Heat is rising.  Summers are warmer and longer.
A clear cut scientific issue becomes a “political” issue when science itself is disregarded, denigrated and derided by those who have something to lose by keeping the planet habitable.  The data on global climate change were fairly overwhelming fifteen years ago, and now they’re worse.   We don’t just get hot.  We get cold. Freezing. Drowned.  The arctic melts, plants migrate into Antarctica oceans, ticks spread.  Human diseases change as does our ability to grow food.
People remain wedded to the linear fallacy – the idea these shifts are occurring along a straight line.  But that’s not how biology works.  There are tipping points.  Go without drinking on a hot, humid day, and the mild headache abruptly  progresses  to heatstroke.  The same is true of climate. At a certain stage, protective factors morph into exacerbating ones; the permafrost does not just take up heat, but releases its content to flood the atmosphere. The “linear progression” turns into an asymptotic curve, a hockey stick.  Soon we’re not living on a planet we recognize.

Just as the planet needs protection, so do you.  Keeping hydrated helps.  Keeping cool is equally important.

Simple, effective means:  clothing that covers you and lets the sweat stay on your body, as uncomfortable as that may be. Wearing hats, which prevent dehydration, heat stroke and skin cancer.

When To Hydrate

Before going outside is best.  Then when out, sip.  And continue to drink when you’re back inside. Most of our water losses are called “insensible” because we don’t sense them.

How To Hydrate

Water usually is the easiest, most delectable substance.  But we also lose salt and solutes.  In severe cases, we can use salt tablets for working in the Houston sun.  Yet food may be best.

People forget how much of their food is water.  When going out in a hot sun, fruits like apples, pears, bananas, oranges, are fine and add healthy solutes. Many fruits are more than 80% water.   Fruit juices are more like sugar drinks, a direct pipeline into your gut and liver.  In a population where 170 million adult are overweight or obese, sugar drinks may not be the best hydraters.

How Much is Enough?

People vary dramatically in their overall use and secretion of fluid.  If it’s 111 degrees and you’re hiking the Arizona desert, you may well want a liter or more fluid each hour.  Over a standard day, most of us do okay with 3 liters.  When it’s hot, we need more.

That extra half gallon of fluid can prove helpful for hot, humid summer days.  Arguments that you need to keep your urine clear may not really hold water.  Drink when you feel thirsty. Drink to  replace your sweat, and ideally so that you don’t sweat too much.  Athletes know that.  So should we.

Common Problems

Lots of us love tea and coffee.  Many a summer whiles away with iced tea.  Yet both coffee and tea are mild diuretics, prone to lose more solute and fluid than we gain imbibing them.

Coffee and tea are worthy food-drugs.  Frequent coffee consumption can decrease population risk of diabetes and Parkinson’s disease.  Green tea helps keep us from lingering disabilities. Yet in the middle of a hot hot day, they may not be the best solution.

Follow you ice tea with water and fruit.

Overhydration is also another worry.  It is possible to drink too much.  But it’s hard.  You have to drink enormous amounts. Unless you have problems with absorption,  GI and kidney function, most of the time we expel excess fluid easily and rapidly.  In general, underhydration is a considerably great problem than excess.

Bottom Line

You need food to live.  You need sleep to live.  The majority of your body is water, so you need fluid to live.

It’s easy to stint on drinking outside in summer.  It’s not enjoyable carrying water.  It interferes with fun things to do.  Yet it’s necessary for your well being.

So drink to your health. Drink for it, too.