I'm thinking of Lindemann's pamphlet about Tesla's self-acting engine, and have this idea:

1. Put a tube which spirals down then up inside a suit with good insulation.
2. The tube has a check valve at each end, so we can call the ends intake and outlet.
3. Outlet is connected to a throttle fixed to the upper back of the suit.
4. The throttle is connected to the inlet of a centrifugal generator also fixed to the upper back of the suit.
5. Intake is connected to the output of the generator.
6. The tubes are filled with liquid that boils around 30? degrees c.

Hopefully the centrifugal generator would steal enough motion from the atoms that the liquid would cool without use of a compressor.

The major problem is the throttle. I'm trying to think how it could be designed without the use of electronics. It needs to let the pressure build up, then release and stay open until the pressure equalizes, then close. If there's such a valve, please give a link. Nothing I think of works.

You need a safety valve with a mechanical delay on return to closed position. This will open easily when the pressure is too high, but not close until the pressure is much lower than it is before the valve opens.
You need to let the valve open easily, but use a break on its way to close.
This site for example have something you might need:
http://www.generant.com/relief-valve.shtml

Thanks

Speaking out of total ignorance I'm not sure if those valves would work, but the keywords led me to some information I'm trying to grok:

http://books.google.co.uk/books?id=S5nkOjXQkEIC&pg=PA96&lpg=PA96&dq=relief+valve+mechanical+delay&source=bl&ots=nNeVK_PZYH&sig=lsO8kz8PrGAvp-o0TF85isf_-gQ&hl=en&sa=X&ei=Lbh5T_X9NfOR0QXCvsijDQ&ved=0CGMQ6AEwAA#v=onepage&q=relief%20valve%20mechanical%20delay&f=false