The camping aisle on the Thursday before a long weekend

It's 4:40 on a Thursday and the whole store smells like new nylon and rubber. The fuel canister shelf has been picked down to two cans of the wrong kind. Every cart holds the same cargo: a cooler, a tarp, and a man who "just needs a few things." I've been that man. I was in this aisle last year. The aisle had plenty to say.

Heard in the aisle

"I'll figure out the tent when we get there."

The real lesson: Pitch it in the backyard first. Count the poles and stakes, find the torn seam, and learn which sleeve the long pole goes through while there's daylight and a hose nearby. Doing it for the first time at dusk with a headlamp in your teeth is how a weekend gets its first argument.

"The bag says 20 degrees, so I'm good down to 20."

The real lesson: That number is usually the lower limit, the point where you survive, not where you sleep well. Look for the comfort rating and buy for it. And pair the bag with a real pad, because the ground pulls heat out of you faster than the air does. For near-freezing nights, look for an R-value around 4 or higher. The Ground Steals Your Heat Before the Air Ever Does explains why.

"Cotton's fine. It's only a little rain."

The real lesson: Wet cotton stops insulating and takes a long time to dry. Wool and synthetics keep working when damp. Jeans and a cotton hoodie are fine for the car ride. Pack something else for the woods.

"I'll run the little stove in the tent. It's pouring."

The real lesson: Don't. Never run a stove, lantern, or grill inside a tent or a closed-up vestibule. They put out carbon monoxide, which you can't see or smell, and it kills people in their sleep. Cook under a tarp or in the open, with the wind at your back.

"The creek's crystal clear. I'm just going to drink from it."

The real lesson: Clear water can still carry giardia and other bugs. Filter it, treat it with tablets, or boil it for at least one minute (three minutes above about 6,500 feet). A forty-dollar filter beats a weekend in the bathroom.

"I've got my phone flashlight."

The real lesson: You also have a phone that's your map, your camera, and your only way to call anyone. Burn the battery on a flashlight and it's gone by the time you need it. Buy a headlamp, carry spare batteries, and keep your hands free for the work. The ten essentials include light for a reason.

"I'm bringing firewood from home. Free, and it's seasoned."

The real lesson: Don't move firewood more than a few miles. It carries insects and diseases that wreck forests, and many campgrounds restrict it. Buy it near where you'll burn it. Check for burn bans before you leave the driveway. When you're done, drown the fire, stir the ashes, and don't walk away until the coals are cold to the back of your hand.

"My wife said to grab a second tarp. We don't need two tarps."

The real lesson: She was right. She's usually right about the tarp. One over the kitchen area and one over the tent site turns a soaked Saturday into a decent one. Buy the second tarp. Also buy extra cord, and tell her she was right before the rain does.

"We'll just text everybody the plan if something comes up."

The real lesson: Cell service quits where the trail gets good. Before you leave, tell someone you trust the trailhead, the route, who's with you, and the time they should worry if you're not back. Then actually come back by that time, or get word out. Don't make them guess. The first overnight backpacking trip piece goes further on this.

"Do the campsites have trash cans?"

The real lesson: Plan on packing out every scrap you bring in, and bring a spare bag for it. Bury human waste in a hole six to eight inches deep, at least 200 feet from water, trails, and camp. Leave the site cleaner than you found it, even if the last people left a mess. Especially then.

Before you go

• Shop Monday, not Thursday. The week before a long weekend, the right fuel canister is the first thing to vanish.
• Bring the old canister. An empty one shows the clerk the thread type, so your stove and fuel match.
• Bring your numbers. How many people, how many nights, and the coldest overnight low in the forecast. A good clerk can fit gear to that in two minutes.
• Bring a photo of your tent and your stove. If you can't remember the model, the picture can.
• Check fire restrictions and road conditions for where you're headed. If it's your first trip with the kids, make it one night. That's plenty.