You first need to investigate whether the water you use for bathing is free of germs and worth using. It may not be affecting the others, but it can affect you if you have sensitive skin. The other important thing you need to know is your skin type. I feel you have dry skin
. If your skin is of dry type than it is better for you not to take a "pretty warm shower". Your skin is reacting to it. Normal skin has its natural lipids
that keeps it soft and problem free. But dry skin is unprotected, pretty warm shower makes it worst. You can use a mildly warm water with which you are comfortable. Limit your shower to a shorter time.
You should use a good quality moisturiser ( applicable for dry skin ) and apply it immediately on your damp body after shower. Make sure you have patted soppy wet body with a clean towel. If you apply moisturiser after your body is completely dry the moisturiser will be of little help to you. Try this with a correct moisturiser that suits your body and you will be fine in a few days. Continue to do it, do not stop once you are relieved of your problem.
In dry skin itches usually emerge in areas like abdomen, limbs
, arms and legs. These tend to go away soon. Dry skin can be due to careless eating habits. Eat well balanced fresh, nutritious home made food rich in anti-oxidants and minerals, keep yourself well hydrated, protect your skin when you go outdoors. Add legumes, cereals, eggs and dairy products in your diet. Since you are getting them in your mouth pay special heed to healthy eating. They can arise due to some vitamin deficiency
. Prefer wearing full sleeved shirts and full pants or jeans. It will keep your skin soft and supple. Avoid using harsh cosmetics, deodrants and strongly scented soaps or perfumes. Have a good day.