Hi and welcome! Work as best you can during probation. Show up every day and be willing to do what you're told. Ask questions if you don't understand.
The heat's hard on all of us. Take a frozen gatorade and/or frozen bottle of water to sip on. If you feel overheated, sick to your stomach or dizzy let them know. Better to sit down for a few minutes than to keel over. Not worth the risk. You're only human!
Some people don't make it through probation. It's a rough, stinking nasty job at times and I've seen many good people just not like it. No shame in that at all. What you see during probation is what it will always be like. Chaotic, loud and sometimes just plain senseless. Good luck and let us know how you're dong.