The Collaborative International Dictionary of English v.0.48:

Miliaria \Mil`i*a"ri*a\, n. [NL. See Miliary.] (Med.)
   A fever accompanied by an eruption of small, isolated, red
   pimples, resembling a millet seed in form or size; miliary
   fever.
   [1913 Webster]

WordNet (r) 3.0 (2006):

miliaria
    n 1: obstruction of the sweat ducts during high heat and
         humidity [syn: prickly heat, heat rash, miliaria]