Is your hotel room radioactive?

That hotel king bed might not be as clean as you once thought. The Nuclear Regulatory Commission opened up an investigation this week querying how difficult it has been for hospital patients to spread radioactive contaminants across the nation, including on public transportation and in hotel rooms.

The problem stems from a particular treatment given to thyroid cancer patients, a dose of radioactive iodine that stays in the system and can emit a low level of radiation after the subject leaves the hospital. In turn, this emission can contaminate public places such as buses, hotel rooms and other highly trafficked locales.

Usually the NRC has strict rules on where one can travel after radiation treatment, but in a recent case, a patient left the hospital in New York and headed straight for an Atlantic City hotel — leaving atomic traces of radioactive iodine scattered along the way. Radiation sensors picked up the patient in the Lincoln Tunnel and set authorities hot on the trail.

There’s more info on the NRC’s investigation and input from congress over at Yahoo’s AP Newsdesk. Until then, make sure you bring your Geiger Counter with you next time you’re headed to a hotel.