Palm get cold in winter. Active thyroid?

During winters I develop various skin related problems. My palm and feet get cold and get colder as winter escalates. And sometimes when body gets heated due to exposure in sun or due to activity I get red rashes along with lot of irritation on the body especially chest. And in winter only I have skin flakes on palm and feet more than what is normal. Apart from these symptoms in winter I also have problem of dandruff, grey hair and hairfall round the year. And testicular torsion in winter which is painful at times. But none of these is severe. Plus I always have boil/pock marks on my back just below the neck. I used to have a lot of mouth ulcer earlier which is not that frequent now and non severe chronic constipation too. I have gone to doctors and took medication for a month but to no avail. i was not properly diagnosed and they asked to come in winter. I need to know the cause of all this. Are these symptoms connected? Could it be due to under active thyroid? Pleas enlighten. Thanks