Our bodies react to any increase in temperature by perspiring. Sweat is released from the body via sweat glands located in the dermis, and this sweat-secretion process helps the body maintain its temperature as sweat evaporates from the skin.

So why does getting hot and sweaty give us a healthy glow? While little scientific data exists supporting the link between sweating and detoxification (as the body’s other exocrine glands are sufficiently equipped to get rid of what it doesn’t need), sweating is a form of excretion, so it makes sense that perspiration will aid in toxin and waste removal, leading to healthier skin overall.

Heat also increases circulation, enabling blood to bring vital oxygen and nutrients to the skin’s surface. This increased blood flow gives the skin an instantly healthier appearance by creating the rosy, flushed glow that’s synonymous with optimal health and vitality.

In high-humidity environments like steam or hot yoga rooms, added moisture in the air encourages the skin to maintain suppleness and hydration. In addition, the process of steaming cleanses skin from the inside out by encouraging the release of bacteria and debris from the pores. Though pores cannot technically open and close, loosening pores via steam helps expel bacteria and debris that may lead to enlarged pores, blackheads, whiteheads, and other acne symptoms.

Sweat dissipates more slowly in moist environments and may breed bacteria if allowed to sit on the skin, potentially worsening skin disorders such as acne and psoriasis. Therefore, it is important to remove makeup before a sweat session, as it blocks pores and prevents sweat from escaping; properly cleansing the skin after a steam room, sauna, or hot yoga class is another simple way to keep bacteria at bay. Sauna-goers should also moisturize after cleansing, as dry sauna air can dehydrate the skin.

Heat, too, is a known aggravator for patients suffering from rosacea, a disorder characterized by bouts of skin redness, flushing, and pimple-like bumps. Case in point: In a 2010 survey published by the National Rosacea Society, 56 percent of participants reported that indoor heat was a trigger for rosacea flare-ups. Patients with rosacea should minimize their exposure to extreme heat, or better yet, skip extreme heat-related activities altogether.

Finally, as our bodies are composed of approximately 70 percent water, replenishing water lost to sweating is absolutely critical during, before, and after activities that significantly raise body temperature. And, as with any lifestyle change, check with your doctor before spending any time in saunas, steam baths or hot yoga rooms to confirm whether or not they’re right for you.

Reference:
http://www.rosacea.org/press/archive/20100525.php
Authored by Karen Sticka; Physician Assistant, Dermatology Office of Dr. Ellen Turner, M.D., Dallas, TX in Ask a Skin Care Specialist on November 3rd, 2013