[Taqwus]

...tend to have short lives, especially when in use by Abysia which makes 'em Extra-Crispy. Would it be possible to grant blood slaves the corresponding national temperature preference/immunity that the bulk of the nation's population has?
(IIRC, any pref of >= 2 in magnitude also matches with immunity; Caelum, Jotunheim, Abysia come to mind at least.)