If you are getting cold at night you may want to either dress warmer or turn up the heat. There are several things that can cause muscle cramps that won't go away. A lack of magnesium, which gets more common as we age, potassium or calcium can do it. Drinking coffee, tea or sodas can wash those minerals out of the body. I take magnesium about every day to prevent cramps and have for about 2 years now. If you don't want to take a pill take a hot soaking bath for about 20-30 minutes with Epsom Salts which is just magnesium & sulfur. You can also take a long soak in a bath with Bath Therapy bath salts, they really help.
If the hot bath alone doesn't help then you probably need the minerals.
If you close your toes real hard that will take it away usually. An it might be not enough potassium in your diet.
dehydration can cause this , not enough water,salt, potassium. magnesium and calcium. eat bananas and drink a lot of water.
I think it means you need salt.
Oh dear. I wouldn't know what to do then in your situation.