So docker is just a wrapper to provide the execution environment for photon in this case. You’ll either have to use docker as it’s really nothing more than installing the docker engine and that’s it, you just run commands provided by the photon dev.
Or
If you really don’t want to use docker for whatever reason, you’ll have to reverse engineer the actual code stack within the Dockerfile in the project that is used to build the image you’d otherwise just run. Again this is more more involved and the whole reason to use something like docker in the first place.
The body is not a perfect thermal insulator so you must note that the liquid in the bladder is constantly losing heat due to dissipation into the surrounding tissues then the environment around the body. The greater the temperature differential between the body and the environment, the faster the rate of transfer. Your body won’t (or at least it’ll try its damndest) to not let that internal temp drop, which will take more and more energy to maintain as the external temp drops.