11.   But burners fueled by propane or kerosene are used to heat air and thus make up for the deficit in helium lift.

12.   Completing a destructive feedback loop, the warmer surface heats the air even more.

13.   Compression heats the air inside and ignites charred denim in the hollowed-out point.

14.   Death Valley typically takes a distant second to the hot spots around Los Angeles when the Santa Ana winds descend and heat the air at the coast.

15.   Each day heated air in the middle of the peninsula rises, and ocean breezes flow toward the land.

16.   If the air is heated by radiators or an electric baseboard, consider using fans to help keep it circulating.

17.   Many indoor space heaters work by heating the air, which would be impractical on an open deck or patio.

18.   Radiation warms the people and objects directly without noticeably heating the air in between.

19.   That is, as the sun heats the top of a mountain, the high ground heats the air in contact with it.

20.   The air was heated by compression at the lower elevations and under sunny skies, it was enough warming for a record!