Romans tried to invade Sub Saharan Africa

Message:

His generals, in the early part of his reign, attempted the reduction of Ethiopia and Arabia Felix. They marched near a thousand miles to the south of the tropic; but the heat of the climate soon repelled the invaders, and protected the un-warlike natives of those sequestered regions. (Gibbon)

Humidity...how long are you vested in armor and holding an unsheathed sword on your Dungeon Crawl?

Yours,