I was on a trip with my wife the first week of June and on our way back from New Hampshire we hit that first heatwave of the season which we were not prepared for (it had snowed North of Toronto just under 2 weeks before). Previously, we'd been camping most nights with the temperatures dipping to 7 degrees overnight, then passing through Vermont into New York on the second last day (Friday) it hit 33 degrees. First time I ever experienced heat exhaustion - fever, nausea, etc. through the night. Riding through the heat that day, I didn't realized I was as dehydrated as I was. It is NOT fun. The next day was also 33 degrees, and we had to travel 700kms to get home – Getting up at 6am to beat the afternoon heat (it was still 26 degrees in the morning). Every hour we stopped to rest for 20-30 minutes in an air conditioned place. Passing through Kingston on the long 401 slab in the heat, felt like a constant blast of hot air.
Stay safe out there. It took me 3 days to fully recover. If it's crazy hot out, make a stop to soak your t-shirt with tap water. Throw the jacket overtop of it, and it'll keep you cool for a good amount of time.
