Perniosis, or chilblains, are skin lesions that occur as an abnormal reaction to cold, damp environments. We describe five cases of perniosis affecting the thighs. Four of the five cases occurred after wading across mountain rivers. Histological changes of deep perniosis and panniculitis were seen in a skin biopsy from one of the cases. In each case there was marked pain and discomfort, and lesions resolved over more than 1 week.