Poor RiRi was sent to the hospital while most were out trick or treating on Monday, and was forced to cancel her concert in Malmo, Sweden. Have no fear, though, it was just a pretty bad case of the flu and she’s already back on her feet! “Sorry Malmo!!! #LOUDtour,” she tweeted from the hospital with a picture of the IV in her arm. No holds barred on her Twitter, huh? Check out the pic below.