The only help is to get as comfortable as possible while undergoing the early symptoms. If the radiation dose was small, the symptoms, if any, will probably go away and not recur. If the symptoms recur after a latent period, you should go to an aid station. Rubble from buildings being knocked down can bury supplies and equipment. Heat can ignite dry wood, fuel, tarpaulins, and other flammable material.
Light can damage eyesight.
Nuclear radiation can contaminate food and water. The best hasty protection against a nuclear attack is to take cover behind a hill or in a fighting position, culvert, or ditch. If caught in the open, drop flat on the ground at once and close your eyes. Cover exposed skin and keep your weapon under your body to avoid loss. If you know the direction of the burst, drop with your head away from the burst.