Avoid heatstroke

Great advice, and not just for travel. It's hot everywhere this summer! I have a "special" sport scarf that is supposed to keep your neck cool, but if you can use any thin washcloth, so much the better -- thanks for the tip.

Thanks for this. A series of Gatorades ingested early in day is necessary in extreme heat, advice from a paramedic.

The ENT told me this during an AZ heat wave, temps were 115. I was fine but others were suffering. Frightening to observe.

RE: And, baloney on the dangers of drinking too much water. OK, don't drink, and see what happens.

As Tom notes, excessive hydration can result in hyponatremia, a potentially deadly condition. An interesting Runners World article
https://www.runnersworld.com/training/a20829769/dehydration-and-hyponatremia-how-common-how-dangerous/
notes that:

"...dehydration doesn't exist as a medical condition. It's not
dangerous in the short-term (a day or two). It's completely normal for
humans to get dehydrated during the day as we rush around taking care
of our various responsibilities. Then at night, when we relax, we
notice that we're thirsty and start drinking. End of dehydration."

"Very severe hyponatremia (<130 mE/L; or, far worse, <125 mE/L) can be
life threatening. Indeed, there have been eight recorded deaths from
hyponatremia in endurance athletes in the last several decades."

https://www.mayoclinic.org/diseases-conditions/hyponatremia/symptoms-causes/syc-20373711

In acute hyponatremia, sodium levels drop rapidly — resulting in
potentially dangerous effects, such as rapid brain swelling, which can
result in a coma and death.

Drink water in moderation. Drinking water is vital for your health, so
make sure you drink enough fluids. But don't overdo it. Thirst and the
color of your urine are usually the best indications of how much water
you need. If you're not thirsty and your urine is pale yellow, you are
likely getting enough water.

In addition. My Kaiser physician agrees w the Mayo Clinic: 8 oz liquid 8 x on any day. More or less depending upon activity and weather. When we traveled in Guatemala with temperatures averaging in upper 90s to 110°, we drank constantly. There we were careful to drink only water in bottles. Never used ice cubes unless you are assured they are from clean water. When we left our filled water bottles in the hot car, I was amazed at how refreshing even hot water is. We rapidly went through our stash of powdered Gator Aide. Their gum was a disaster. In that heat, it stuck to my lips and I had to use cold bottled water to finally get it off! We laughed when the man next to us in a restaurant was drinking from a huge pitcher of watermelon juice. Ha on us. We downed twice that amount. Keep hydrated!

While drinking too much water too rapidly can be a danger, the people advising hydration also suggested Gatorade and/or salt with the water, which prevents the dangerous aspect of drinking too much water - lowering of sodium.

Much of the advice here is good. One thing I'd add is factor in your activity level with the heat. I got heat exhaustion on my last trip to Spain in weather that wasn't that hot. About 29C. Would have been perfect sitting-on-the-beach weather.. But it was fully sunny, mid-day, and we decided to hike up a mountain. The initial incline was extremely steep and I started to feel bad, and not just in a normal "sucks hiking up a mountain" sort of way.

Luckily we had plenty of water and once I realized that something was wrong, we spent a lot of time chilling in the shade. But the initial push that lead to the heat exhaustion was probably only around 20 minutes of activity, and it took me a couple hours to get back to "normal". So be careful!

A bag of nice salty crisps/chips can also help properly balance out blood salt levels. Back during my marathon running days, I regarded a medium order of fast food french fries as the perfect recovery food because there was also enough potassium from the potato to make a difference.

https://en.wikipedia.org/wiki/Siesta

Mental fogginess can accompany dehydration. After a summer day spent in Nevada's high desert with temperatures above 90F, I walked back to my car. I noticed a nice white SUV parked right behind me on the side of the road. I got in my car, moved the gear-shift to Reverse, and backed right into the SUV. It was not a mechanical error, but a mental one. If there had been a human being back there rather than another car, I would certainly have hit him or her.