Canonical: https://cooltimeusa.com/blogs/news/tagged/pcm # Stay-Cool Guides & Cooling Tips | CoolTimeUSA Blog ## PCM [RSS](https://cooltimeusa.com/blogs/news.atom) [**activation temperature**](https://cooltimeusa.com/blogs/news/tagged/activation-temperature), [**cooling neck ring**](https://cooltimeusa.com/blogs/news/tagged/cooling-neck-ring), [**PCM**](https://cooltimeusa.com/blogs/news/tagged/pcm) - August 30, 2026 ## [What Temperature Does a Cooling Neck Ring Activate At?](https://cooltimeusa.com/blogs/news/cooling-neck-ring-activation-temperature) What the 64F (18C) activation point of a cooling neck ring means, why it is the sweet spot for comfort and safety, and why a warm counter will not re-freeze it. [**Read more**](https://cooltimeusa.com/blogs/news/cooling-neck-ring-activation-temperature) [**cooling neck ring**](https://cooltimeusa.com/blogs/news/tagged/cooling-neck-ring), [**how it works**](https://cooltimeusa.com/blogs/news/tagged/how-it-works), [**PCM**](https://cooltimeusa.com/blogs/news/tagged/pcm), [**TPU**](https://cooltimeusa.com/blogs/news/tagged/tpu) - June 26, 2026 ## [What's Inside a Cooling Neck Ring (and How PCM Actually Works)](https://cooltimeusa.com/blogs/news/how-pcm-cooling-neck-rings-work) A plain-English look at what a cooling neck ring is made of and how phase change material keeps you cool. [**Read more**](https://cooltimeusa.com/blogs/news/how-pcm-cooling-neck-rings-work) [**cooling neck ring**](https://cooltimeusa.com/blogs/news/tagged/cooling-neck-ring), [**history**](https://cooltimeusa.com/blogs/news/tagged/history), [**NASA**](https://cooltimeusa.com/blogs/news/tagged/nasa), [**PCM**](https://cooltimeusa.com/blogs/news/tagged/pcm) - June 25, 2026 ## [From NASA Spacesuits to Your Neck: The History of Phase-Change Cooling](https://cooltimeusa.com/blogs/news/nasa-history-of-pcm-cooling) How phase-change cooling traveled from a 1948 solar house and NASA-funded astronaut gloves to the chilled ring you wear on your neck. [**Read more**](https://cooltimeusa.com/blogs/news/nasa-history-of-pcm-cooling)