Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.

Hello, dear readers, and welcome to our monthly letters column. With lengthening days and warming weather, outdoor activities beckon.

Please remember to protect yourselves from the sun, whether with sunscreen, UPF clothing or, ideally, both. Tick protection is also important when you’re venturing into the great outdoors, as the data show tick-borne illnesses are still on the rise. We’ll have a column on the topic soon. Now, on to your letters.

— Speaking of being outdoors, we have written several columns about the mental health benefits of spending time in the natural world. We recently received a question on the topic from a reader in the Chicago area: “Do you get the same good results from being in nature if you’re on the phone the whole time?” he asked. “My brother says he wants to de-stress — but whenever he’s hiking, he’s always wearing a headset and making or getting phone calls.”

Research has found that the sights, sounds, scents and physical sensations of being outdoors can lower cortisol and increase serotonin, each of which can help us feel better. If you’re on the phone, your awareness of these is at best diminished or, at worst, eclipsed.

Your brother’s headset habit doesn’t interfere with the physical gains of the hiking he does. However, it can create a barrier between him and the natural world, and thus diminish, if not erase, the mental health benefits.

— A recent column discussed dandruff, a common skin condition that causes scalp flakes to develop and shed. This prompted a question from a concerned reader: “I’ve been seeing someone who has really bad dandruff and doesn’t seem to be doing anything about it,” they wrote. “The thing I’m worried about is if it’s contagious. Am I going to get dandruff if we sleep on the same pillow?”

Dandruff can be caused by dry or inflamed skin, contact dermatitis or chronic skin conditions such as psoriasis or eczema. Most often it is caused by an overgrowth of a yeastlike fungus. This fungus is naturally present in the scalp, but in some individuals, it leads to an overgrowth of skin cells and results in the flakes we know as dandruff. You will be happy to know that the condition is not contagious.

— We continue to get letters asking for another update to the clinical trial exploring the use of stem cells in the management of Type 1 diabetes. The initial phase of the trial was quite small, with just 17 participants. However, the early results, in which several participants ceased needing injected insulin, hinted at a possible breakthrough.

A new phase of the study has been completed, and we will be back soon with a column on it. We’ll discuss the results, explore the promises and explain the potential dangers of the treatment.

Thank you to everyone who has taken the time to write. We love hearing from you. If it occurs to you, please include your city or state or region in your letter. We really enjoy knowing where you are writing from.

Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health.