Can Icing Your Chest Help You Fall Asleep?

TikTok—the wildly popular social media app that consists of brief snippets of video submitted by users—has a wide range of content from a variety of people. Since any user can post, there is plenty of health advice that is not necessarily sound. Misinformation campaigns, highly edited and misleading videos, and out-of-context health information from people claiming to have more credentials than they actually do are all present on the site. The latest viral health advice, however—strange as it may sound—may actually be based on science.

It involves “icing” your vagus nerve.

Classified as a quick fix for insomnia, this particular TikTok trend claims that if you place an ice pack on your chest, you will calm down quickly and be able to fall asleep more easily. Watched more than 3 million times as of this writing, the idea is that the ice helps stimulate and tone your vagus nerve. Your vagus nerve is the long cranial nerve that extends from the base of your brain through the organs in your abdomen. It plays a crucial role in the function of the parasympathetic nervous system, which calms your body down after its counterpart-- the sympathetic nervous system-- is activated into fight-or-flight (which amps it up).

Low quality sleep, difficulty getting to sleep, and full-fledged sleep disorders like insomnia have all been increasing in prevalence in modern times, and the pandemic has only fueled these challenges. So, it’s no surprise that this particular life hack has gained such enthusiasm among a very receptive audience. So the question becomes: Is it backed by science?

The basic answer is, happily, yes—in part. Early research has indeed shown promise in vagus nerve stimulation having benefits in helping relieve anxiety and fear. And additional research has looked at vagus nerve stimulation specifically as it pertains to insomnia, and the results are encouraging. Vagus nerve stimulation—in the aforementioned study achieved with an implanted electronic device—was associated with an increase in the body’s production of melatonin, which in turn helped study participants fall asleep more smoothly.

And using cold temperatures in particular to stimulate and tone the vagus nerve has been supported by recent research (though it is far from settled, as some contradictory results have been attained as well.)

The bottom line? The sympathetic and parasympathetic branches of your autonomic nervous system are the yin and the yang of your stress response. While the sympathetic nervous system activates you so you can fight or take flight in a threatening environment, your parasympathetic nervous system is what brings you down and helps you relax.

In modern life, most especially these past two years of the COVID pandemic, our stress response has been put through the wringer, with so much asked of it nearly every day in the throes of uncertainty and disruption. Keeping our parasympathetic nervous system in good working order, so that it can step in to bring us down from the height of our fear and anxiety, is crucial in maintaining our mental health. And it is possible, perhaps even likely, that using ice on your upper torso or the sides of your neck can do just that, with at least mild relief even in the moment. It’s the same reason that people who have cardiac events like SVTs, which can result in episodes of dangerously high pulse spikes, are told to stick their heads in ice or snow in order to help bring down their nervous system’s arousal immediately.

So, as TikTok trends go, this one just might have something to it!

Can’t stand the idea of using ice on your body? Thankfully, there are other ways to activate and tone your vagus nerve. Slow, deep breathing—the same types used in the practice of mindfulness meditation and in the relaxation exercises commonly taught in the treatment of anxiety disorders—has also been shown to stimulate the vagus nerve. So too have humming and singing. Over time, exercise and its associated heart rate variability have been shown to keep the vagus nerve in good working order as well, which may very well be behind at least part of the connection between exercise and the diminution of depression and anxiety.

The next time you find yourself laying in bed, mind racing and body feeling anything but relaxed, it’s nice to know that a potential treatment requires no special order or appointment, and is likely ready for the taking in your freezer.