I've been extremly cold for the past year or so i am taking iron pills but i am also 4foot 11 and weigh 105lbs how can i gain weight?

Eat healthy: Gain weight only if it's healthy weight. Eat healthy, exercise regularly, work on being happy. Put on a coat if your cold. Have your thyroid checked as it could contribute to you feeling cold.

Eat healthy foods: that are high in calories. Eat 6 meals /day. Work on strength training to build large muscle groups. Work out w heavier weights w fewer repetitions. Sleep at least 8 to 9 hrs/night. Hydrate well w water. Foods to help w healthy weight gain: almonds, cashews, pecans, sunflower seeds, flax seeds, walnuts, hummus, avocados, granola, trail mix, dried fruits, protein shakes, protein bars, lean meats