What are the potential health risks associated with exposure to 15000 roentgen of radiation?

Exposure to 15,000 roentgen of radiation can lead to severe health risks, including radiation sickness, skin burns, organ damage, and an increased risk of developing cancer. Immediate symptoms may include nausea, vomiting, and hair loss, while long-term effects can be life-threatening. It is important to seek medical attention immediately if exposed to such high levels of radiation.