Blasts from the Past: A look at stories from the pages of National Defense as NDIA and the magazine approach their 100th anniversary.

As National Defense in this issue takes a snapshot of research-and-development priorities in the year 2018, it is always interesting to look back at some of the ideas put forth in the past. The September 1985 issue, which was devoted to land warfare, had an article on microclimate conditioning.

"To protect tank crewmen against a hazard more insidious than enemy action--heat stroke--corporate and government researchers are working on liquid-cooled garments that let each crewman wear his own 'climate,'" wrote Steven M. Shaker and Alan R. Wise.

The A/C in a backpack weighed only...