Yeah that's near freezing temperatures for me. I ended up in hospital just after 10 seconds of going under the ice, so I'm hesitant about this, knowing that my body can react severely to extreme cold. I do take colder showers. I start warm, then dial it to as cold as I can take (usually down to say 10 degrees). I stand like that for a minute or so, then get out refreshed. I think I'm just going to start slowly with 'colder than my body temp' showers. (E.g. I'll start at 15 degrees, then work my way down).