The hottest temperatures of the year so far, combined with high humidity, could push the heat index in Central New York to nearly 100 degrees on Wednesday. The heat index is the measure of how hot it feels given the temperature and humidity. High humidity makes it harder for the body to evaporate sweat and cool off. The combination of heat and high humidity can be dangerous for people who are outdoors. Tuesday will be hot, with a high of 90, but the humidity will likely stay below 40 percent. Wednesday and Thursday, however, will be hotter with higher humidity, and the heat index could reach into the high 90s both days. Wednesday could even break a record for the date, which is 94, set in 1995. Three days in a row of 90 or above constitutes an official heat wave in Central New York. The last time that happened was last year, from Sept. 6 to 9. This week, nights will be warm, too, with temperatures staying in the 70s Wednesday and Thursday nights. High temperatures fall back into the mid-80s on Friday.