Do I really need a heavy winter coat?

No. A packable down jacket combined with a waterproof shell is warmer and far more versatile than a bulky parka.

How do I handle the laundry with such different types of clothing?

Stick to synthetic or merino materials. They dry quickly, don't hold odors, and can be washed in a sink if you get in a pinch.

Packing for South America: From Sea Level to High Altitude

To handle South America's temperature swings, pack exclusively in layers rather than heavy coats. Prioritize a technical shell, a packable down mid-layer, and high-quality merino wool base layers that can be combined or shed depending on your elevation.

Master the 'Three-Layer' rule. Bring a moisture-wicking base layer (merino wool), an insulating mid-layer (down jacket or fleece), and a windproof/waterproof outer shell. You will wear these in tandem in the Andes and peel them off in the Amazon or coastal cities.
Select versatile footwear. Bring one pair of broken-in waterproof hiking boots for trails and one pair of lightweight walking sneakers for cities. Do not pack heavy, dedicated snow boots; if you are going to extreme cold, buy cheap extra socks to wear inside your hiking boots.
Use compression cubes. Because you are packing for two climates, use compression packing cubes to shrink your puffer jacket and fleece. This saves 30% of your luggage space.
Prioritize high-altitude protection. The sun is significantly stronger at 3,000+ meters. Pack a wide-brimmed hat, polarized sunglasses, and a high-SPF sunscreen, as you will burn twice as fast in the Andes as you would at the beach.

Do I really need a heavy winter coat?: No. A packable down jacket combined with a waterproof shell is warmer and far more versatile than a bulky parka.
How do I handle the laundry with such different types of clothing?: Stick to synthetic or merino materials. They dry quickly, don't hold odors, and can be washed in a sink if you get in a pinch.