If the last time you had a plantar wart removed was a decade or two ago, you might remember your doctor dabbing liquid nitrogen onto a medical-grade Q-Tip to freeze the hard, grainy growth away. That technique is still around, but new developments in the use of cold therapy for a vast range of conditions are heating up.

Aside from things like skin tags and those ugly warts, “cryotherapy” is now used to treat certain types of cancer; to reduce inflammation, decrease joint pain, and increase athletic performance (whole-body cryotherapy); and to, purportedly, blast away targeted fat areas like “muffin tops” and love handles (CoolSculpting). (There’s also cryonics, used to freeze human bodies in the hopes of a future cure, but that’s one use that’s not yet available in Vancouver.)

The actual methods vary from one form of cryotherapy to the next, but all centre on the use of extremely cold temperatures to achieve the desired effect.

Perhaps the trendiest is CoolSculpting (based on the trademarked “science” of “Cryolipolysis”), which is centred on the idea that cold can selectively affect and eliminate fat cells without damaging the skin or surrounding tissue. It’s marketed as a nonsurgical approach to fat reduction.

“The key about this type of cryotherapy is that the temperature is just so that fat cells would be frozen but the overlying skin, blood vessels, and adjacent muscles would be unaffected,” says Shannon Humphrey, cosmetic dermatologist at Carruthers & Humphrey and clinical instructor in the department of dermatology and skin science at UBC. “Different tissue types freeze at different temperatures, and there’s a very particular response when fat cells are frozen: they change. They actually are damaged, so they express certain markers on their cell membranes, and the immune system sees the cell as damaged or destroyed and gobbles them up and clears them away permanently.”

The technique is intended to target localized bulges or pockets of stubborn fat in people with stable body weight who have a healthy diet and lifestyle and who exercise regularly, Humphrey says.

“It’s not a treatment for a patient who is significantly obese or who has fluctuating weight,” Humphrey says. “It’s not perfect…but for those patients they can get somewhere between 20- and 30-percent reduction in bulge with a single treatment.”

A session involves lying down with a device over the area to be treated, with the patient feeling pressure and intense cold. Results take three to eight weeks, and sometimes several sessions are needed. Prices vary, and most places that offer the service don’t advertise fees online. Rather, you have to call to get more information, with some centres hiring aggressive sales representatives to take calls and do follow-up queries.

Although Humphrey, whose clinic offers the treatment, says it has been well studied, others say more evidence is needed to determine the lasting safety and efficacy of CoolSculpting.

“I believe the old-fashioned approach is still the best: getting your lifestyle and diet under control,” says naturopathic doctor Brian Davies, founder of Westcoast Integrative Health. “Quote-unquote muffin tops are a classic example of what happens with hormones over time. It really frustrates both sexes—certainly women…but men as well—dealing with weight gain around the midsection.

“The quick fix is not often lasting,” Davies adds. “That’s where frustration can come in. Our body can re–lay down fat if it chooses to do so….I think it’s [CoolSculpting] fairly new, and with anything new, time will be the essence in saying if it’s a worthwhile, effective treatment or not.”

With whole-body cryotherapy, people sit in a single-person cryosauna or a multiperson cryochamber where parts of their bodies are exposed to ultralow temperatures, -200 ° F to -240 ° F, for short durations, about one to three minutes. Supposedly, the therapy, which was first used in Japan about 40 years ago, works by triggering the body’s regulatory systems as the skin-surface temperature drops significantly.

The procedure is now used to relieve pain and inflammatory symptoms caused by numerous disorders, particularly those associated with rheumatic conditions, and it is also used for the treatment of arthritis, fibromyalgia, and ankylosing spondylitis. In sports medicine, it has become a way to improve recovery from muscle injury. On offer at some spas, the therapy was deemed “not harmful” in healthy subjects in a 2010 study published in the journal Sports Medicine.

Cryotherapy is also being used as a relatively new prostate-cancer treatment. Also known as cryosurgery or cryoablation, it consists of a minimally invasive surgery using controlled freeze and thaw cycles to destroy the disease. According to the Vancouver Prostate Centre, a UBC and VGH Centre of Excellence, cryotherapy is not used as often as radiation therapy as a primary treatment because it lacks sufficient long-term-survival studies.

However, it is effective in treating cases of prostate cancer that are radioresistant and recur as a result. As cells freeze, ice crystals form inside and around them. The freezing and thawing processes destroy cells through dehydration, drastic changes in the pH levels, or prevention of the flow of red blood cells, according to the centre. Plus, subjecting the prostate gland to freezing temperatures activates an antitumor response in the body.

The least controversial use of cryotherapy is to treat skin lesions such as warts, sun spots, skin tags, and benign or premalignant moles. Liquid nitrogen, which has a temperature of almost -200 ° F, can be applied with a cotton-tipped applicator or through a probe that has cartridges of liquid nitrogen that is delivered like an air-gun shot.

“This has a long, time-tested track record,” Humphrey says. “It has a favourable side-effect profile. It hurts a little bit. We typically don’t use any local anesthetic, but it stings. Following treatment, it does throb a little bit.” Some people have no side effects, while others have redness and swelling.

A probe is more effective than the old-fashioned Q-Tip-style application, Davies says.

“One of the advantages is different tip sizes that equate to the lesion size in millimetres,” says Davies, who has also used the device successfully to remove small tattoos.