The Yukon Quest test


2007-report about the Jervenbag Thermo Extreme

The Yukon Quest.


- First I want to mention that the Jervenbag Thermo Extreme was the best addition to my equipment.

At the start of the YukonQuest 2007 I had no idea that it would become one of the coldest races ever. The first half of the race the temperatures were around -20 to -30 Celsius. Normal temperature for Canadas Yukon Territory and Alaska in Februar. 


All photos by Carsten Thies, official YukonQuest Photographer.

Mostly I used the bag to sit in while waiting next to the trail for mushers. Sometimes it took hours before a dogteam appeared. I kept all my layers on. Long heavy underwear, skipants, fleecepullover, light downjacket and my Refrigiwear Overall, belaclava and light gloves. As boots I used Sorels and if it was real cold, below -35, I use Bunnyboots. I left all my clothes on and crawled in the Jervenbag. At -30 it was so warm that I had to open the zipper. Soon the temperature dropped to -40, it was nice and comfortable in the bag that sometimes I dozed off. Since I wore my heavy Refrigiwear Overall I didn't use a ground sheet and I didn't miss it. No change when the temperature dropped to 49 below. I was sitting or laying in the bag without moving.

On the Yukon River I used the bag directly on the snow, or I dug a little trench. In the hills I used spruce twigs as an insulation. I didn't think of pitching a tent and I didn't miss my down sleepingbag, although in the long run a down sleepingbag will be more comfortable.


All photos by Carsten Thies, official YukonQuest Photographer.

I never felt cold or miserable. The biggest disadvantage was the humidity inside, at all temperatures. I tried to use a candle. The candle was in an empty can which I held in my hands. It worked as far as it felt drier and more comfortable. But in the narrow bag I had to move carefully, I didn't want to set the bag on fire.

I also used the bag to change a shirt or socks. It was so much nicer to it inside than exposed to the cold. The zippers worked fine all the time, since I followed you advice and greased them with silicone grease.

I had hoped to store the cameras with me in the bag. But that was not easy, since the cold-soaked cameras would fog up immediately. Just like if you would take them into a cabin. I had to put the cameras into plastic bags to prevent them from condensation. Or I left them outside in a special camera backbag which I heat with chemical heating pads.I wished I had the Jervenbag Thermo Kingsize, since the Thermo Extreme was close to the limit. I am 187 cm and 92kg, the heavy wintergear added to the diameter. A bigger size would be a plus.The armings didn't fit over my arm with the downjacket on.


When I traveled on the Quest trail by snowmachine it felt good to have the Jervenbag with me. I look at it as my most valuable piece of survival equipment. It sure helps you to stay warm. I don't want to miss it and I think it is a must for every trapper, hunter, dogmusher or snowmachiner who is outdoors at very low temperatures.
-This bag is a life insurance!

Carsten Thies, official YukonQuest Photographer
Londoner Str. 40
13349 Berlin


About The Yukon Quest:
At the top of the world in the Yukon-Alaskan Interior, an epic event takes place every year that few people from ”down south” have experienced. Covering 1000 miles between Whitehorse Yukon Territory and Fairbanks, Alaska during the depths of the Artic winter, the Yukon Quest is known as the “toughest sled race in the world”.                 Official website: click the banner above.

The test above is about the Jerven bag Thermo Extreme.

Click here if you want more information about the Jerven bag Thermo Extreme.

Links to another dog-sled races:



Notice: In Finnmarksløpet in Norway, you are not allowed to start unless you have a extreme survival-bag.