Concord, California reached a high of 112 degrees Fahrenheit on Saturday, twelve degrees hotter than the previous record high for July 22 in Concord, a record set in 1996. The air was filthy and still.
I climbed Mount Diablo anyway. Not all the way. I’m not crazy. I’m not the kind of guy who’d go out in 112-degree weather and hike a little over 14 miles with a nearly 4,000-foot climb. No, I got to Juniper Campground and turned around. Call it 10.5 miles and just under 3,000 feet climbed. A small effort: a sane effort, really. A compromise with the implacable heat.
And it wasn’t really 112 degrees the whole way. In fact, to be quite honest, along shadier sections of the trail, as I lay panting on my back waiting for my heart rate to slow, a breeze would pick up on occasion and I would look at my little zipper-pull thermometer and see that the “mercury” had dropped just a hair below 100 degrees. I’d put one of my Camelbak water bags in the freezer the night before, a practice I heartily commend. I was still sipping ice water five and a half hours into the hike.
Which raises a question. You are hiking in 112-degree heat, climbing 3,000 feet. In your pack you have 100 ounces of delicious 32-degree ice water from your tap in Pinole, piped direct from the clean and refreshing Mokelumne River in the Sierra Nevada. You have another 100-ounce container of water in there as well, full of chalky, salty tap water from Yuma, its source the saline wastewater canal formerly referred to as the Colorado River. That water is the temperature of the inside of your pack. Call it 80 degrees, what with the inferno outside and the block of ice next door. At the outset of the hike you have no idea how much water you will need, nor do you know how long the ice water will stay cool. Which do you drink first? Do you enjoy the ice water while you can, or do you gamble that it will stay cold until the brackish stuff is gone and you’ll truly appreciate it?
I split the difference: I ran the tubes from both reservoirs through the rings on my pack straps and took sips from each one in alternation. I also decided to freeze both reservoirs next time out.
Despite the cold water, my blood felt thick after the first two miles. My heart raced, pushing unwilling, tacky red blood cells through sticky capillaries. When the temperature is a mere forty degrees cooler, I hike that hill these days without pausing to catch my breath. On Saturday I was forced to find a shady spot in which to lie down every third switchback, feeling my heart pound as though throwing a rod. And then would come the slowing, and the delicious, luxurious cool breeze, and I would look at the thermometer: 102. Blessed relief.
The worst of it was not going up. Going up I at least had a happy question occupying my mind: How far before I turn around? I promised myself it would be just at the next patch of shade. And then the next one. And the next. At Deer Flat I met a woman as insane as me, who climbed Kilimanjaro last year and summits Diablo once a week with hikes in other local parks making up the rest of her weekly schedule, and we chatted for a few minutes and she ruefully admitted she had only made it as far as Juniper Campground, which became my destination as she spoke it. On the last long steep pitch before the road levels out toward the campground I took a nap mid-way, the only shade my hat held overhead by a trembling arm. Piece of cake, really. Temperature in the breezy shade of the campground: 103.
No, the hard part was on the way down, every bit as hot but with less excuse to rest each hundred yards, and I got back to Deer Flat and my shoes were on fire. I napped on the bench of a picnic table, my bare feet drying on the table, my block of ice removed from the pack and balanced on my forehead. And then the switchbacks, 600 feet of them in a mile, and my feet rebelled again. Where Mitchell Creek comes out of the mountain it is cold, too cold to leave your feet in there for more than a minute, cold enough to cause actual pain in your hypothermic toes. My feet needed slaking, and they took me through wilting grape and poison oak to a small plunge pool. I walked around in it for a good four minutes, near-audible gasps of relief coming from each foot, and then sat on the bank waiting for my toes to dry before re-shoeing.
It didn’t help. By the time I’d laced the second shoe, they were inflamed again and I was sweating worse than ever. I wore only a thin wicking-poly t-shirt, a scarf, running shorts, in sum as near to naked as safe and legal and still retaining far too much heat, and I took a long look at myself and my prospects of making it the next two level miles to the truck.
The external iliac veins drain blood from the legs and feet — supplied by the external iliac arteries, and collected by the femoral veins — and channel it toward the heart. You have two: one for each leg. Along the way, in the lower abdomen, tributaries join them: the inferior epigastric veins, the deep circumflex iliac veins. The internal iliac veins flow in, Missouris into each Mississippi, the watersheds combined forming the common iliac vein, which empties into the inferior vena cava and into the heart, which pumps it to the lungs to be oxygenated, and then back to the heart for redistribution throughout the body.
The upstream limit of the external iliac veins, where the femoral veins flow into them, is very close to the surface of the body. It is at the inguinal ligament, the great divide between thigh on the one side and belly and pubis on the other. The external iliac veins carry a lot of blood: your legs are about as big as a human organ gets. Were a person to desire to cool the core temperature of the human body in short but safe order, applying something cold to the inguinal ligaments would do it: chilling the blood in the external iliac veins would distribute that cold throughout the body pretty quickly. So after some minutes of increasingly confused and cloudy deliberation, I sat in the water as long as I could. It was forty-five seconds, I think, or a minute, the water coming up only just past my umbilicus, where the iliac veins dump into the inferior vena cava. And then I put on my shoes and walked back to the truck, cool and comfortable and deciding whether the thermometer read 113 or 115. It really is hard to read. I ought to find myself a better one.