An 80-year-old male was admitted to our hospital because of near-drowning in a hot spring. Besides hypoxia, serum calcium was extremely high at 15.5 mg/dL on admission. After the treatment with normal saline infusion, furosemide and calcitonin, the hypercalcemia was transient and didn’t recur during the course. The hot spring water contained much calcium, so his hypercalcemia was considered to ...