Five hundred years ago, Sudor Anglicus was known as “the sweating sickness” since the hot and sweating stage of the illness occurred often before death.
The English 'sweate' (Sudor Anglicus)
A rapidly fatal viral infectious disease appeared in England in 1485, persisted for the summer months and disappeared as winter approached. This pattern of infection re-appeared in 1508, 1517, 1528, and finally 1551. The epidemic never returned. It had no respect for wealth or rank, and predominantly attacked males between the ages of 15 and 45 years. The incubation period was frighteningly short and the outcome normally fatal. The symptoms of acute respiratory disease and copious sweating were characteristic, providing the name 'the English sweating disease'. It was never in the big league of killer epidemics, such as plague and influenza, but its pockets of instant lethality in communities gave it a special ranking of horror. The infective cause of this disease remained a total mystery...If I ever see Justin Welby sweat, I will know that the end of the Anglican Communion is near. Maybe that is why he is holding the upcoming Primates meeting in the middle of winter instead of in the heat of the summer.
From Br J Biomed Sci. 2001;58(1):1-6. which speculates about the Hantavirus as a possible cause.