Red Next To Your Head

I was having a light-hearted discussion on “field uniforms” with a friend. The idea was a practical uniform that could be used for general tasks rather than as a dedicated combat dress. I believe the latter role would be better served by combat smocks that can be worn over body armour.
One source of inspiration was the British battledress. I was also looking at the Afrika Korps. Why the Afrika Korps? Unlike most European combatants, Germany had very few colonial holdings so when they went to war in Africa they had to design everything from scratch. It was a useful crucible to determine what traditional uniform features they were using were worth keeping. The first attempt included high lace-up boots, breeches and a sun helmet. Experience in Africa produced radical changes in the uniform. Ankle-length boots with trousers that could be bloused into them, or shorts, became commonplace. So too did a long shirt which could be worn instead of a tunic (and also served as a nightshirt!). The most distinctive uniform item, however, was the peaked Afrika Korps cap.

During my reading I turned up the interesting piece of information that these caps were lined with red material. Some green aircrew clothing has an orange lining. The idea is that if the crashed crewman wants to be seen rather than camouflaged he wears the item inside out. If a similar idea was intended for the Afrika Korps cap, why red and not some other colour that might be more visible in desert conditions?

It is possible the red lining was intended for another form of signalling. Placing a luminous panel inside a patrol cap is described in this article.But if signalling with the red interior of a cap was a common technique why did later German army designs of headwear not have a red lining too? I have a post-war BW hat of similar design, but no red lining.
Another possibility was that the red cloth was the cheapest cloth available. A friend who is an English Civil War reenactor has often pointed out to me that “many civil war regiments on either side wore red. It was often the cheapest cloth that could be had”. Including in this was Cromwell’s New Model Army, establishing the penny pinching and “just make do” traditions that the British Army has struggled with for so many centuries!
The actual answer is in fact far more interesting. Red lining was believed to improve protection against the sun. Read more on this topic here!