Welcome to health care magic! I have read your question, the symptoms you have are- single sided head ache, which gets precipitated by hot wether (sun exposure), and it lasts for a long time, may be whole day till you take medicine. From my clinical experience I can tell that these look like migraneous headaches. Symptoms like one sided headache, female gender, headaches when going out in sun, headaches when one remains hungry for long, excess of work /stress, near periods, etc are commonly seen in migrane. It is quite a common condition but under treated and troublesome. However responds sufficiently to treatment. In my patients I have found that medicines like amitryptiline and propranolol regularly for some time and a pain killer as and when required had wonderful results in migraines. Along with the medicines, avoiding the trigring factors as mentioned above reduces the frequency and intensity of migraines. Hope this helps you staying away from headaches! Feel free to ask more regarding this.