DIY: cheap icepack for your lower back

Whenever I do something physically stressful, like going on a fast walk, or anything that involves prolonged bending over or lifting, there's always a risk of pain afterwords. To lower that risk, I've found it very useful to apply an icepack to my lower back immediately after the exercise, even if there is as of yet no pain. To make this easier, you can make an icepack you can strap onto your back, allowing you to ice your back while still being able to move around the house. Here, I show you how to do that out of common household items.

The trick is to take a dress shirt, put a bag of peas just below the collar, and then tie the arms of the shirt around your wast. To demonstrate this more clearly, I recorded a video of how to do this.