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I got a splitting headache two hours into the trail because I thought a Nalgene and some ibuprofen would cut it. Spoiler: they did not. These kept me functioning above 4,000 meters on my second attempt.
















The weather swung from sunburn-hot to freezing rain in about forty minutes. I watched a guy in jeans and a hoodie turn around at the halfway point. Don't be that guy.














Parts of the trail are loose scree, parts are muddy from snowmelt, and the last kilometer is basically a scramble. My running shoes were a terrible idea the first time around.
















UV at nearly 5,000 meters will cook you faster than you think. I got sunburned through cloud cover and my eyes were watering for two days after. These fixed both problems.
















You don't need a 50-liter pack for a day hike, but you do need the right stuff organized so you're not digging through your bag while gasping for air at 4,500 meters.
















Most people fly into Lima and bus to Huaraz overnight. You need at least two days to acclimatize before attempting Laguna 69, and what you do in town matters as much as what you carry on trail.














