Friede, 57, from Wisconsin, has spent nearly 20 years injecting himself with snake venom to build immunity.

His work may now help solve a major global health problem: Each year, venomous snakes bite up to 2.7 million people, causing an estimated 120,000 deaths and 400,000 injuries, The New York Times reported.

In a two-minute video, Friede is seen calmly allowing two deadly snakes—a black mamba and a taipan—to bite his arms. Despite bleeding from both arms, he smiles and says, “Thanks for watching.”