I have swollen red patches on my legs and arms that feel warm to the touch for a few days.

It sounds like you may be experiencing an allergic reaction or eczema, as red, swollen patches accompanied by itching are common symptoms of these conditions. To help alleviate your symptoms, you can try using cortisone cream on the affected areas, taking an oral antihistamine like Benadryl or Reactine, using colloidal oatmeal in your bath, and moisturizing your skin regularly with a cream containing ceramides. It's important to make sure these products are safe for you to use, especially if you take other medications, have known allergies, or have any health issues. If your symptoms worsen or persist, it's a good idea to consult a pharmacist or doctor for further advice.