Most of the Southwest is now under an excessive heat warning, with days last weekend reaching 100 degrees or higher.

In Cottonwood, temperatures average about 5 degrees hotter than Sedona, while downriver in Camp Verde, which is lower in elevation and doesn’t benefit from clouds forming over the edge of the Mogollon Rim, temperatures are generally a bit hotter than Cottonwood.

Local agencies issued warnings to stay cool and hydrated and find shelter in case your home doesn’t have a working air conditioner or swamp cooler.

I was living in the East Valley of the Phoenix area the day it hit a record 122 degrees: June 26, 1990. We humans can notice subtle differences in temperatures close to our own body temperature, but higher or lower temperatures are harder to determine. So for most people, including heat-hardy Phoenicians, there isn’t much to notice between 110 and 122 degrees.

I’ve said that atmospheric awfulness has a threshold around 107 degrees, when temperatures go from “hot” to Dante Alighieri-esque infernal and the specific number becomes moot.

One summer when I was attending Arizona State University, a local business in Tempe made light of the heat by hosting an egg-cooking contest using the hoods of contestants’ cars.

While those of us with decades of Arizona blood in our veins are used to coping with excessive ambient heat that can melt the rubber on tennis shoes, many new residents, especially those hailing from cooler climes, are not.

Avoiding the heat and staying hydrated is key. New residents who may not be used to drinking a lot of water daily need to be reminded to do so now that they live in the Arizona desert. If you’re used to humid heat elsewhere, Arizona is different. Visitors and new residents may think merely finding shade is sufficient, but it’s not. Often these people think they’re weathering the heat, pun intended, better than they really are.

You sweat to cool off, and in Arizona’s dryness, people who don’t sweat a whole lot have sweat that evaporates quickly. The “dry heat” we joke about also indicates that we lose a lot of moisture through our skin, so drink far more water than you think you might need to offset any moisture you may lose.

Tourists and visitors especially need to be aware of the dangers of hiking without sufficient water. All too often I have seen tourists on trails with 8-ounce water bottles at the start of a hike, which is woefully insufficient.

If you do decide to go hiking this week — well, we can’t fix stupid — but if you do, pick a trail that has plenty of shade cover. Temperatures start out warm and are near their peak around 2 p.m. Don’t be on a trail around then. Temperatures stay high until about 4 p.m. before they start cooling off.

Take a hike along shady Oak Creek or the Verde River instead. Carry loads of water for yourself and your crew and some extra. If you come across anyone on the trail who looks dehydrated, ask them if they need some water and be willing to share.

It’s an urban legend that it’s against the law in Arizona to not offer water to people, but you would be hard-pressed to find any business that would not provide water to a passerby who asked for a drink, especially in summer.

Be wary about taking a dog or a child on the trail this week. Young children don’t know the dangers and are trusting you to keep them safe. Dogs can’t object or consent to a hike and don’t know what a forecast is. They regulate their heat differently than we do and most are wearing fur coats. Taking a dog hiking in 105-degree temperatures isn’t fun, it’s cruelty.

Coyotes are canines native to the Southwest. They stay in the shade during the day and wait out the heat. Take their cue.

Instead of a hike, go to the creek. Wade in the water and go swimming. We have stories about swimming holes on our website in case you’re looking for a new place. Take your young kids to the Splash Pad at Sunset Park or to the Sedona Community Pool.

We’re not expecting any monsoonal relief at least until the middle of July. We might have clouds rolling in, offering respite from the heat, but temperatures will likely stay at 100 degrees or higher until the storms begin.

Until then, please stay cool, hydrated and safe.