My skin gets itchy wen the temperature rises even little bit. its uncontrollable. and i usually have very dry skin?

Sounds like eczema.: Eczema is in the same family of conditions as allergies and asthma. It can't be cured but usually can be controlled. It is best managed by using a sensitive skin cleanser, avoiding bathing in very hot water, and using a sensitive skin lotion at least 3 times daily, even when the rash isn't there. If doing this doesn't help enough, please see the doctor.

Hive or dry skin: I am not sure about the question. Skin conditions such as hives, and eczema (frequently associated w dry skin) can become more itchy with rise in body temperature.