The tropical Southeast Asia (especially the Malay world, e.g. Malaysia/Indonesia) are very hot, and apparently wearing European-style full armor is very uncomfortable in hot climates.
What kind of armor, if any, did the heavy infantry/heavy cavalry soldiers in the region use before the introduction of gunpowder (or other developments which renders armour obsolete)? I think they must have not encountered European armoured soldiers, and due to the heat they might have less reason to develop heavily armoured soldiers.
Do we have any records of how they were armoured before the European's arrival? Maybe during the 14th-15th century?

