However, itâs also a time to be aware of the dangers soaring temperatures can bring. Extreme heat is the number one weather-related killer in the U.S, claiming more than 650 lives across the nation each year, according to the Centers for Disease Control and Prevention.
1 In a bowl whisk together garlic, extra virgin olive oil, balsamic, 1/4 cup red wine, 1 tablespoon chopped rosemary, salt and pepper.  Place flat iron steak in a resealable plastic bag. Pour marinade over the top. Shake to coat steak in marinade. Refrigerate for 8 hours or overnight.
Place the flat iron steak in the marinade and cover the dish with its lid or plastic wrap. Put it into the refrigerator. Soak the beef in pineapple or papaya juice marinades for about an hour. If it's buttermilk marinade, leave it in there two to three hours.