It seems like the person is texting us that he is at risk. Since the type of risk or disaster is not mentioned, we can make possible guesses and give him following support:
• First of tell him to calm down and ask him what type of risk is he facing and his location.
• If he has faced man made calamities like theft, abduction, then call the nearest police station. Give the police his picture, phone number, address and other details so that they can track him down. We should also try to reach the place as soon as possible.
• If he has faced some road accident, then call the ambulance and police to reach there as soon as possible. We should be also there as soon as possible to give him support.
• In case of fire, call the fire brigade, ambulance and police giving them all the information and urge them to reach there as early as possible.