Palm Springs in January

Merino or synthetic, since this is the layer that sits under everything else and cotton stays wet.

SmartwoolSmartwool Merino Sport 120 Long-Sleeve Shirt - Men's$85Shop at REI →IcebreakerIcebreaker Merino 125 Cool-Lite Sphere III Long-Sleeve - Women's$100Shop at Icebreaker →PatagoniaPatagonia Capilene Cool Merino Blend Long-Sleeve - Women's$62.30Shop at Backcountry →ColumbiaColumbia Tech Knit Long-Sleeve Crew - Men's$27.49Shop at Columbia →

REI members usually get 10% back on full-price gear. Membership is $30, once. How it works

Merino, not cotton. It stays warm when it's damp and still doesn't smell on day three.

Arc'teryxArc'teryx Women's Satoro Merino Wool Crew Neck Long-Sleeve Base Layer Top$95.73 was $120Shop at REI →REI Co-opREI Co-op Women's Merino 185 Long-Sleeve Crew Base Layer Top$84.95Shop at REI →Arc'teryxArc'teryx Women's Lana Merino Wool Crew Base Layer Top$63.93 was $90Shop at REI →TerramarTerramar Men's 3.0 Merino Bi-Layer Long-Sleeve Crew Base Layer Top$29.73 was $45Shop at REI →

One pair for every two days, plus two.

SmartwoolEveryday Merino Bikini Underwear - Women's$34Shop at Backcountry →SmartwoolEveryday Merino Thong Underwear - Women's$34Shop at Backcountry →SimondSimond Trek 500 Merino Wool Backpacking Underwear Women's$29.99Shop at Decathlon →REI Co-opREI Co-op Women's Merino Hipster Underwear$29.95Shop at REI →

Trail runners dry overnight where boots take days, which is why most people prefer them on warm trails.

CraftCraft Women's Endurance Trail-Running Shoes$130 was $175Shop at REI →KiprunKiprun Kipsummit Men's Trail Running Shoes$130Shop at Decathlon →KiprunKiprun Kipride Women's Running Shoes$140Shop at Decathlon →ScarpaScarpa Ribelle Run Trail Running Shoe - Men's$116 was $179Shop at Backcountry →

Buy it used: REI Re/Supply sells gear like this for less. See used gear

Polarized kills glare, but the tag has to say 100% UV separately, and that's the part your eyes need.

ZealZeal Isabelle Polarized Sunglasses - Women's$67.03 was $149Shop at Backcountry →CostaCosta Caleta Net 580G Polarized Sunglasses - Women's$174 was $248Shop at Backcountry →SmithSmith Cheetah Polarized Sunglasses - Women's$93 was $155Shop at Backcountry →ZealZeal Bennet Polarized Sunglasses - Women's$59.60 was $149Shop at Backcountry →

10,000mAh is about two phone charges, 5,000 barely gets you through one long day.

Top pickGoal ZeroGoal Zero Venture 75 Power Bank$120Shop at REI →BioLiteBioLite Charge 80 PD Power Bank$99.95Shop at REI →AnkerAnker MagGo Power Bank (10,000 mAh, Slim)$80Shop at REI →AnkerAnker Power Bank (30W, Fusion, Built-In USB-C Cable)$40Shop at REI →

65W or more charges a laptop. Anything smaller only keeps up with phones.

Peak DesignPeak Design 65W Dual Slim Charger$64.95Shop at REI →Peak DesignDual Slim Charger$64.95Shop at Peak Design →AnkerAnker Wall Charger (33W, 2-Port) with USB-C to USB-C Cable$25Shop at REI →AnkerAnker MagGo Wireless Charging Station (3-in-1, Foldable Pad) with Charger and USB-C Cable$100Shop at REI →

35 to 45 liters fits most cabins. Check your airline's size limit first. Most won't take much over 40L in the cabin.

Top pickMatadorMatador 45L Global Travel PackSee price15% off with CHRISANDSARAShop at Matador →PacsafeGo Carry-On 44L Backpack$180Shop at Backcountry →Osprey PacksOsprey Packs Archeon 30L Backpack$132 was $265Shop at Backcountry →MatadorMatador GloberiderSee price15% off with CHRISANDSARAShop at Matador →

Hard shell protects what's inside, soft shell squeezes into a tight bin, and either way check the size with wheels included.

CotopaxiCoraza Suitcase - Carry On$295Shop at Cotopaxi →SamsoniteHyperflex ∞ Carry-On Spinner$126 was $180Shop at Samsonite →SamsoniteVirtuosa Spinner$154 was $220Shop at Samsonite →ThuleThule Aion Carry On Spinner Nutria$350Shop at Backcountry →

15 to 25 liters.

MammutLithium 20L Daypack$135Shop at Backcountry →CotopaxiElqui 24L Daypack$100Shop at Cotopaxi →CotopaxiConsuelo 22L Daypack$120Shop at Cotopaxi →Osprey PacksOsprey Packs Arcane Large 20L Daypack Botanica$65.97 was $110Shop at Backcountry →

Get locks marked TSA approved. Security can cut anything else off to search your bag.

MatadorMatador BetaLockSee price15% off with CHRISANDSARAShop at Matador →PacsafePacsafe ProSafe 620 TSA Accepted Luggage Locks$17.95Shop at REI →KnackKnack TSA-Approved Lock$16Shop at Knack Bags →ThuleTSA Cable Lock$17.95Shop at Backcountry →

It runs on Find My, so this one's for iPhones.

AppleApple AirTag (2nd Gen, 4-Pack)$95.99Shop at B&H Photo →AppleApple AirTag (2nd Gen)$29Shop at B&H Photo →eufyeufy SmartTrack Link (2-Pack)$19.99Shop at B&H Photo →

Rechargeable over USB-C, so it shares a cable with everything else you carry.

BioLiteBioLite Dash 450 USB-C Rechargeable Running Headlamp$69.95Shop at REI →BioLiteDash 450 Rechargeable HeadLamp$69.95Shop at Backcountry →FenixFenix HM50R V2.0 Rechargeable Headlamp$59.95Shop at REI →Black DiamondStorm 450 Headlamp$38.47 was $69.95Shop at Backcountry →