I'm tempted to just whine "It's too hot!" But we go through this almost every year the first week of June, when spring days with highs in the 60s and lows threatening frost, suddenly turn into a solid week of humid 93 degree days.
Someone must have an active strategy to acclimate to the heat. Because mine consists of just sitting around on my butt, counting unavoidable household and yard chores as my workout, until eventually the temperature drops back down for a while, and by the time these temperatures come back around again in July or August, my body's ready for it.
I like the heat, really I do. Just - not all of a sudden!