I read your problem with interest but it does seem some form of physical or heat/cold induced urticaria
Dermatology however, is a very visual line & as such, requires some clear visual digital photographs or to be seen on the ground by a dermatologist
nearest you for best results!
Please take a non-sedative antihistamine namely 180mg fexofenadine
taken once a day that is safe but may require a prescription in your parts.
Worst case scenario is that a skin biopsy
may be required to help clear the diagnosis & for further management.
Cheers & Godspeed!
Dr Praveen Rodrigues MD