Feeling very weak and cold all the time.could it simply be iron deficiency?

Maybe: It could be iron, or another issue such as a thyroid problem, or anemia. These are easily evaluated with an office visit and lab work.

It could: Iron deficiency would cause you to be anemic which could then cause you to experience the symptoms you are describing. Your doctor could easily diagnose this with a simple blood test. Other possible causes for your symptoms need to be excluded as well

Tiredness: Hi, it could be Iron deficiency anemia or Thyroid problem or untreated allergy, plz see an MD for further evaluation.