What Causes A Itchy Bump On The Chest?

Hi, I would appreciate your opinion on my problem. This afternoon I had a really itchy and hot blush on my chest, and as an intend to relief the itchyness/hotness I putted a really cold ice on my chest, after a little I started feeling a pressure in my chest. Since then until now I've had a headache, some strange dizzyness and the chest pressure persist. What should I do?

Thanks.