Many cases of urticaria produced by cold have been reported. The case to be reported is interesting not only because of the severity of the attacks but also in view of the extensive family history of urticaria caused by the same physical agent. REPORT OF CASE Mrs. R. M., aged 25, has had "all her life" an eruption which comes on when she is exposed to cold. In very cold weather when she goes outside even for a short time urticaria appears in about half an hour. This is accompanied by a chill and fever, the temperature ranging from 101 to 103 F., which lasts from four to six hours. Often there occurs a stiffness of the joints, with erythema of the adjacent tissues lasting from six to eight hours, and if the exposure is great enough it may last twenty-four or even forty-eight hours. At times headache accompanies an