From jungle to glacier: how to layer for an adventure

Kathmandu Ambassador Tim Jarvis explains how he uses just four layers to go from 30 degree temperatures in the equatorial rainforest to minus 15 on frozen glacier peaks.

At the zero-latitude of the equator, only 25 mountains still have glaciers. In another 25 years, they will all be gone. That’s right, zero ice.

Environmental explorer Tim Jarvis and his team are chasing down these remaining glaciers to showcase their beauty, raise awareness about the effects of climate change on our planet, and raise funds to do something about it.

The project is called 25zero and it takes Tim from steamy jungles at sea level to cold, alpine conditions as high as 6,310 metres (on Ecuador’s Mount Chimborazo).

A casual Tim Jarvis on one of his many expeditions.
A casual Tim Jarvis on one of his many expeditions.

On these expeditions, Tim and his team have to cope with a huge range of conditions. And they have to do it with just a few garments.

The trick? Layering.

“Layering is super-important for all that I do,” Tim says. “You can get away with two layers on the bottom and four layers on the top to go anywhere.”

“With my 25zero project, you’ve got 32 degrees celsius and 90% humidity in rural Indonesia. You’re on an island, drinking cold beers and just wearing a t-shirt and then at the top of the mountain it’s minus 15 degrees and there is 25km of wind.”

Tim also has to prepare for everything in-between. It’s a five-day trek to reach the Carstensz Pyramid, the highest mountain in the Papua Province in Indonesia.

You can’t afford to take 10 different garments. You need three or four key layers that you can interchange and that fit on top of one another that allow you to regulate temperatures as best you can.

Tim Jarvis

At 1500 metres the base layer is fine for day hiking but a light fleece layer is needed at night when the temperatures drop to 12–15 degrees.

“You go higher again and when you get up to 2,500–3000 metres, you’ll need the base layer with the thermal layer for daytime travel. You’ll have that plus a waterproof shell when you get higher again, all the way up to summit day when you might have a total of four layers.”

At this point, Tim says, the base layer’s main function is to wick moisture away from your body. The second layer adds thermal insulation. The third layer might include some windproofing, and the fourth layer is the important waterproof layer.

“In the tropics, even at altitude, tropical storms come through in the afternoon.”

High alpine climbing is done at night: “You want to be up and down and back in camp before you get the torrential rain event about 3pm.”

But if they miss this window — the waterproof outer shell is vital protection.

“And when you’re walking in, you certainly have to walk through that afternoon rain to cover the ground.”

25 peaks. Four layers. And one strategy: layering.

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Tim Jarvis is a Kathmandu ambassador, environmental scientist and founder of the 25zero project. He was named Australian Geographic’s Conservationist of the Year 2016.

Follow the 25zero project on Instagram @TimJarvisAM or YouTube.