The present invention relates to an oil-based cosmetic having the innovative, unprecedented property in which the ultraviolet protection effects increase due to heat. The oil-based cosmetic of the present invention contains



(A) an ultraviolet protectant; and
(B) at least one compound that is water-soluble and that has an IOB of 5.0 or lower, selected from among (i) alkylene oxide derivatives and (ii) polyhydric alcohols;

wherein
the (B) (i) alkylene oxide derivatives are polyoxyalkylene/polyoxyethylene copolymer dialkyl ethers represented by the following formula (I):

R1O-[(AO)m(EO)n]—R2  (I)



wherein R1 and R2, each independently, denote a hydrogen atom or a hydrocarbon group having one to four carbon atoms, AO denotes an oxyalkylene group having three or four carbon atoms, EO denotes an oxyethylene group, 1≤m≤70, 1≤n≤70 and m+n≤40; and

the oil-based cosmetic has a water content of 5% by mass or less.