Suddenly, it's summer: Dangerous heat wave, humidity, UV levels begin Sunday

For anyone who's put off installing those bedroom air conditioners or cleaning the filters on their heat pump, well, now's the time to do it, because summer's going to hit the Rochester area big-time on Sunday when the heat index will reach 100, an uncomfortable shock to the system for most.
After a fairly comfortable day today, the heat will begin to build on Saturday with a high of 85, but a heat index of 90 with humidity on rhe rise.
The first day of the forecast heat wave begins in earnest on Sunday with high humidity and temps in the mid-90s, with a heat index of 100.
It only gets worse on Monday and Tuesday with highs of 92 and 102, respectively, with heat indexes in the low 100s.
Meanwhile, high or very high UV levels that will be in place throughout the heat wave can cause immediate harm like sunburns and long-term damage such as skin cancer and cataracts.
Thunderstorms Tuesday afternoon will bring temps down, but the humidity will linger into Wednesday,