 Rapid onset tiredness, weakness, dizziness, headache, fainting, all of these things. Here's what to do, basically. Some important tips from the Bear River Health Department. Immediately move yourself to a cool place. If you have come upon someone you feel is suffering heat stroke, maybe they're even unconscious, immediately move them to a cool place. Do not try to treat them standing there in the sun or the heat. Get them to a cool place. Loosen your clothes. Sip. Don't gulp.