Stuffy unventilated rooms.    From Wordnet, Princeton University. 

It often occurs in unventilated tenements on stifling nights.    From Wordnik.com.  [The Home Medical Library, Volume I (of VI)] Reference

No windows, unventilated, oppressively hot, a setting for intimidation.    From Wordnik.com.  [CNN Transcript May 5, 2003] Reference

Others attribute it to the close unventilated hats commonly worn by men.    From Wordnik.com.  [Hygienic Physiology : with Special Reference to the Use of Alcoholic Drinks and Narcotics] Reference

All new, unused and unventilated travel trailers have formaldehyde in them.    From Wordnik.com.  [Formaldehyde and travel trailers] Reference

Night air is not as objectionable as the confined air of unventilated rooms.    From Wordnik.com.  [Minnesota; Its Character and Climate Likewise Sketches of Other Resorts Favorable to Invalids; Together With Copious Notes on Health; Also Hints to Tourists and Emigrants.] Reference

That blas was triggered by an accumulation of gas in an unventilated tunnel.    From Wordnik.com.  [At Least 74 Dead in China Mine Blast] Reference

Both bathrooms and the fancy range hood are vented into the unventilated attic.    From Wordnik.com.  [In which our rose-colored glasses are torn off, stomped upon, and smashed into tiny little pieces.] Reference

I met him in an unventilated interrogation room that smelled of bleach and paint.    From Wordnik.com.  [After Iraq] Reference

Someone told animal services that dogs were being kept locked in an unventilated shed.    From Wordnik.com.  [Montgomery County animal watch] Reference

"I don't believe that Alcatrante knew that this place was unventilated," she remarked at last.    From Wordnik.com.  [The Girl and The Bill An American Story of Mystery, Romance and Adventure] Reference

Approximately this amount could kill 500 people, if delivered correctly in an unventilated room.    From Wordnik.com.  [CNN Transcript Feb 29, 2008] Reference

Young Mr Estate Agent hurries us past the windowless, unventilated bathroom and its odour of damp.    From Wordnik.com.  [flat hunting] Reference

You may recall they were found packed inside his unventilated tractor trailer back in May of 2003.    From Wordnik.com.  [CNN Transcript Dec 4, 2006] Reference

Nineteen illegal immigrants were killed when they were crammed into an unventilated tracer trailer.    From Wordnik.com.  [CNN Transcript Dec 23, 2004] Reference

Thirty detainees were held in an unlit, unventilated cell roughly six feet wide by twenty feet long.    From Wordnik.com.  [Cambodia: Hun Sen and the 1997 Coup] Reference

However, if you broke five bulbs in a small unventilated room then you might be in short term danger.    From Wordnik.com.  [2008 January 05 « Unambiguously Ambidextrous] Reference

He slept in small, unventilated hovels, a dozen other persons often dividing with him the scanty space.    From Wordnik.com.  [Lippincott's Magazine of Popular Literature and Science Volume 17, No. 102, June, 1876] Reference

Doing hard work in an unventilated cisterna would soon deplete the oxygen content of the atmosphere in it.    From Wordnik.com.  [Working in enclosed spaces, a terrible tragedy] Reference

We sized and sorted the clothing in the hot unventilated upstairs storage rooms of our operations building.    From Wordnik.com.  [Fisher, Donald E.] Reference

These measurements assume a hypothetical unventilated room, not a standard home, according to Llope's study.    From Wordnik.com.  [Buzzword: Radon] Reference

In small unventilated spaces like a closed room or a jet cockpit, the fumes can accumulate to harmful levels.    From Wordnik.com.  [In Israel, a Health Threat in a Fighter Jet - The Lede Blog - NYTimes.com] Reference

In the first American prisons, inmates were confined in crowded, dark, unventilated, filthy, windowless rooms.    From Wordnik.com.  [A Renegade History of the United States] Reference

(These measurements assume a hypothetical unventilated room, not a standard home, according to Llope's study.).    From Wordnik.com.  [Buzzword: Radon] Reference

My condition is the result of insecticide sprayed monthly and weekly for years in a closed, unventilated office.    From Wordnik.com.  [Firedoglake » Pull Up a Chair…] Reference

It is agreed by all persons who have investigated the subject, that unventilated stable air is injurious to animals.    From Wordnik.com.  [Common Diseases of Farm Animals] Reference

They were rented out for fifteen or twenty dollars a month (600 or 700 baht), barren, hot, and unventilated as an attic.    From Wordnik.com.  [Corpus of a Siam Mosquito] Reference

I was starting to be seriously worried about you, and this is for Daniel you are dreaming of the hot, unventilated badminton gym.    From Wordnik.com.  [Beth is no longer a human Crock-Pot, normal programming to resume!] Reference

When that loved one has been hanging by the neck for two days in a warm and unventilated room, the sight would be truly horrifying.    From Wordnik.com.  [Harvest] Reference

I heard a consumptive say that he left a sanatorium for a day class after trying for three nights to sleep in an unventilated ward.    From Wordnik.com.  [Civics and Health] Reference

An atmosphere confined about a house by too dense foliage is, like the air of an unventilated room, not fit for practical purposes.    From Wordnik.com.  [Hygienic Physiology : with Special Reference to the Use of Alcoholic Drinks and Narcotics] Reference

It was a narrow, ill-lighted, unventilated apartment, bitter with the after-taste of taxes, prophetically flavorous of taxes yet to be.    From Wordnik.com.  [The Atlantic Monthly, Volume 13, No. 80, June, 1864] Reference

Nineteen people suffocated in the back of an unventilated tractor-trailer last year as they tried to cross the border near Victoria, Texas.    From Wordnik.com.  [CNN Transcript Dec 23, 2004] Reference

To be sure, the day was warm and the house was unventilated.    From Wordnik.com.  [Baddeck, and That Sort of Thing] Reference

She worked in "an unventilated vault, about the size of a double garage".    From Wordnik.com.  [Stuff.co.nz - Stuff] Reference

The children are no longer crowded together in small, unventilated rooms.    From Wordnik.com.  [Country Life in Canada Fifty Years Ago Personal recollections and reminiscences of a sexagenarian] Reference

Science has not yet decided which is the more fatal, decayed vegetables or unventilated rooms.    From Wordnik.com.  [The Complete Project Gutenberg Writings of Charles Dudley Warner] Reference