I don’t really care about downvotes, but those of you doing so… you might want to actually look into the research behind it. I picked a couple of random links for it because there’s literally nothing special about any of it, along with an NIH article about brown fat recruitment. The science is solid. It’s not a magic bullet; it’s not a replacement for healthy eating or real exercise; it does work for raw calorie burning and for making your body system more efficient at staying warm through calorie burning long term. That’s what our bodies are made to do. It’s a great calorie balancing supplement with very little actual effort.
Shivering is a great easy way to burn calories, and increase the rate you burn calories later through beige fat recruitment.
This should NOT be used to replace healthy eating or proper exercise, but shivering burns gobs of calories to produce heat, and the brown fat (located mostly in your back around neck and shoulders, used just for producing heat from fat) recruits surrounding white fat and transforms it into beige fat (basically converts normal fat into leaky heat-generating fat) to increase the heat generation, and thus calorie burn, of subsequent shivers.
Here’s some links about it, if you are interested. It may not be actionable in the summer, but if you have a basement floor you can lay on, a tub of cold water, or access to a walk in freezer, you can get a healthy shiver going any time.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8341719/
https://www.discovermagazine.com/health/shiver-yourself-thin-can-being-cold-help-you-lose-weight
