Some people do get colder than others

Q: Why is it that when I’m outside with friends in the winter, it seems I always feel colder than everyone else, even when I am dressed just as warmly? — Carmela V., Syracuse, New York

A: Different people’s bodies develop different cold tolerances.

When you’re in the cold, the network of blood vessels close to your skin’s surface retreats inward so you don’t lose heat. But you end up with cold fingers and toes. Some folks’ blood vessels make a deeper retreat.

The body does try to help out by making you shiver: When muscles contract and release, they create heat and warm you up. But how much heat you lose — and howwarmyoustay—depends on lots of factors:

Body fat: Themorefat right under the skin, the more insulated your body is and the less heat you give off.

Height: Generally speaking, the taller you are, more skin area your body has. That means more opportunity for heat to escape.

Age: Older bodies are less able to regulate temperature and are more cold-sensitive.

Gender: Vasoconstriction, that retreat of the blood vessels and resulting cold fingers and toes, happens more to women. Fluctuations in menstrual hormones also can make women more sensitive to cold at certain times of the month.

Underlying conditions: It’s possible that hypercoldness might indicate an undiagnoseddisordersuchasraynaud’s phenomenon or an autoimmune condition such as Sjogren’s or Hashimoto’s.

Other research shows that exercising regularly boosts your resting metabolic rate, so your body produces more heat.

Q: My sister had breast cancer and needed a double mastectomy. After that and almost two years of chemo, she seems to be clear, but she won’t talk about how she’s feeling. She freaks out over little things, like home improvements and getting her car fixed. Does she have PTSD? — Betsy O., Falls Church, Virginia

A: Good question. Support and counseling for breast cancer patients has been going on for a long time.

But linking cancer patients directly to PTSD is long overdue: Many of the successful treatment options for PTSD can help cancer survivors get back to the lives they had before they were diagnosed and treated.

Your sister should be evaluated by a therapist certified to treat PTSD. She can find a qualified psychiatrist at http://finder.psychiatry. org. She can find a support group through the hospital where she had her surgery.

Email questions for Mehmet Oz and Mike Roizen to youdocsdaily@sharecare. com.