Stress is always harmful for thinking good, your brain won’t work that much when you are stressed. So, sometimes it’s better, not to trade when you are tired of feeling stress. It’s because, you may not remember each rule you follow and may make some mistakes in your trades. Which makes huge losses here. I once place 250 pips stop loss instead on 25 pips and the next morning I found my trade went almost 60 pips against my trade and close the trade with 36 pips loss, which was caused by tiredness. So, metal refreshment is very important issue for us.