Nerdy thought exercise: Who would experience a drop in core body temperature faster, the buried avalanche victim or the buried tree well victim?
One study found in the Wilderness and Environmental Medicine Journal had an answer. But first, let’s consider the differences between the snow in each case.
An avalanche victim is typically surrounded by very dense and compact snow as a result of the forces involved with an avalanche. It’s like concrete.
The snow surrounding trees is much different. As we know, the snow crystals of tree wells are typically much larger and have less cohesion, this creates lower density snow with much more air. For a review on the dangers of tree wells, see this article: What to do if you friend is buried in the tree well.
One study found in the Wilderness and Environmental Medicine Journal had an answer. But first, let’s consider the differences between the snow in each case.
An avalanche victim is typically surrounded by very dense and compact snow as a result of the forces involved with an avalanche. It’s like concrete.
The snow surrounding trees is much different. As we know, the snow crystals of tree wells are typically much larger and have less cohesion, this creates lower density snow with much more air. For a review on the dangers of tree wells, see this article: What to do if you friend is buried in the tree well.
Do you know the "Avalanche Climate" of your area? Found out now.
It’s reasonable to think that there could be a difference in rates of heat loss and core temperature drop between the avalanche vs tree well scenarios. The study mentioned above took eleven lucky volunteers and measured their core body temperature and vitals in a simulated avalanche and tree well scenarios with controlled burial positions and snowpack densities. Vitals includes respiratory rate, minute ventilation, end tidal CO2, oxygen saturation, and heart rate.
The collected data showed a faster core body temperature drop rate in the avalanche victims vs the tree well victims. The average expected time to hypothermia (35C) was 185 minutes for the avalanche victims and 250 minutes for the tree well victims. There was no significant difference in vital signs.
The collected data showed a faster core body temperature drop rate in the avalanche victims vs the tree well victims. The average expected time to hypothermia (35C) was 185 minutes for the avalanche victims and 250 minutes for the tree well victims. There was no significant difference in vital signs.
Learn how to treat hypothermia in the backcountry
Okay, so the buried avalanche victims gets colder faster when compared to a buried tree well victim. So what does this mean in the real world? This information is very interesting but for rescuers, it does not change much for how one would respond to and treat buried victims. Rescuers should always anticipate and be ready to treat hypothermia in the field, especially victims buried in the snow, regardless of how long the victim was buried. But this does make for an entertaining thought discussion.
For a review of the Wilderness Medical Society hypothermia guidelines or the new WMS avalanche guidelines, click here. The paper the this study can be found here: http://www.wemjournal.org/article/S1080-6032(17)30244-2/fulltext
For a review of the Wilderness Medical Society hypothermia guidelines or the new WMS avalanche guidelines, click here. The paper the this study can be found here: http://www.wemjournal.org/article/S1080-6032(17)30244-2/fulltext