Conceptual Balance Mod 1.5

[Squirrelloid]

Originally Posted by Sombre

They might spend lots of time huddled around geothermal outlets.

I thought it was fairly warm deep underground, not chilly. I'm no expert though.

I was just in caves two weeks ago that had ice all summer while the temperature above ground was 90+ (Deg F).

Here's a decent link on the subject: http://www.newton.dep.anl.gov/askasci/env99/env223.htm

Note that since many or most areas have seasonal temperature fluctuations, average temperature can be pretty chilly. In most of the US we're talking <=55 deg F.

(As you get deeper, cave temperature becomes more dependent on geothermal heat and less dependent on surface heating - which could lead to warmer or cooler caves depending on the area's average temperature. You have to go quite deep for geothermal to be 'quite warm' - deeper than any known natural caves and probably deeper than its possible to mine out tunnels.)