There are methods better than a text to get a hold of someone. Phone, emails, whatsapp, twitter, facebook, calling the conference management, calling colleagues

There are methods better than a text to get a hold of someone. Phone, emails, whatsapp, twitter, facebook, calling the conference management, calling colleagues at the conf, go nearby the stage at the beginning of the talk. Oh and try to be there on time if you need to do something that critical.