I just read this in a trivia newletter:

"Because it is continually losing body heat, the shrew must keep moving to stay warm. If inactive for more than a few hours, the animal will lose enough body heat to freeze to death."

How can it freeze to death unless the ambient temp is below 32F, 0C?

I am not sure if this answers your question... but it seems to have the right information.

I don't really know. All I know about shrews is that they have a huge appetite and must eat every few hours otherwise they will die from starvation.

Basically, even humans do not actually 'freeze to death' when they die of cold. Your body cannot operate properly at a temperature much below 98.6 F / 37 C. By convention, we call this freezing to death, but the truth is that you would die long before anything actually froze. Shrews cannot maintain the necessary body temperature without moving around.

I guess my point was actually the poor verbage used, "freeze to death."

So what makes a shrew so different in the way it loses body heat than other mammals?

Shrews have a high surface area-to volume ratio. Think of a large block of ice versus many small pieces of ice. The many small pieces will lose their heat more quickly because they have such a high amount of surface area compared to their volume. The same goes for the shrews. they have so much surfacxe area that they lose their body heat rapidly.

I should point out that I'm always cautious of trivia newsletters, websites, etc., and that I haven't actually checked to see if they will die of cold quite that easily, but I do know that they (like all other small animals) have trouble keeping warm due to their high surface area to volume ratio.

Thanks methos, that makes sense.