http://status.nowherejezfoltodf4jiyl6r56jnzintap5vyjlia7fkirfsnfizflqd.onion/productivity/mentalenergy/index.html
This damn cold shower definitely does not feel good, hence it temporarily lowers your dopamine levels, as if you were spending it, but rather you are investing it, because you're going to reap the benefits of a 250% dopamine boost which will last for at least 2 hours ( source ). This means, that if you're willing to bear with that extra discomfort of the cold shower right after waking up, you're going to be able to start your day with more than twice more mental energy...