Ammianus Marcellinus Res Gestae 30.6.3

[3] At this the emperor burst into a mighty fit of wrath, and being particularly incensed during the first part of his reply, he railed at the whole nation in noisy and abusive language, as ungrateful and forgetful of acts of kindness. Then he gradually calmed himself and seemed more inclined to mildness, when, as if struck by a bolt from the sky, he was seen to be speechless and suffocating, ¹ and his face was tinged with a fiery flush. ² On a sudden his blood was checked ³ and the sweat of death broke out upon him. Then, that he might not fall before the eyes of a throng of the common sort, his body-servants rushed to him and led him into an inner chamber.