ST. LOUIS — Summer doesn't officially arrive until next week, but the sweltering heat so typical of the Missouri summertime is already here.
Much of the state is under a heat advisory until at least Monday evening as temperatures in the 90s combine with high humidity to create a heat index of around 100 degrees.
Two deaths in Missouri have been blamed on the heat. On Wednesday, twin 2-year-old girls were found dead inside a car in the southeast Missouri town of Portageville.
Missouri Department of Health and Senior Services spokesman Kit Wagar said the department has received two to three reports of heat-related illnesses virtually every day since June began. He noted that the number is misleading because most people treat themselves without reporting their illness.
National Weather Service meteorologist Butch Dye said that while the June heat wave isn't uncommon, this one arrived a little earlier and is lasting a little longer than most.
"It looks like we're going to stay in this weather pattern at least until the middle of next week or so," Dye said.
In fact, the forecast for most of Missouri predicts temperatures in the 90s and high humidity through the rest of this week and next. Forecasters say temperatures in St. Louis will peak at 94 degrees to 95 degrees through Wednesday.
Some regions are getting hit harder than others. In the southeast Missouri town of Sikeston, Missouri Delta Medical Center has treated five people for heat-related illnesses since last weekend, according to the Sikeston Standard Democrat.
Health officials warn that symptoms of heat stress include dizziness, muscle cramps, headache and nausea.
Wagar said the very young, elderly and chronically ill are most at risk, in part because they are more likely to be taking medication that can impair the body's response to heat, or make it more sensitive to heat. Seniors on fixed income are also more likely to leave the air conditioner off to save money. Relatives are encouraged to check on them to make sure they are safe.
Still, everyone can be at risk. In fact, of the 11 Missourians who died from heat-related causes in 2009, eight were ages 25 to 64.
The heat can also take a toll on dogs, cats and other pets. The Humane Society of Missouri warned pet owners to take extra precautions such as making sure their animals have access to clean water and shade. The St. Louis-based organization encourages animals to be brought inside in cases of extreme heat. And never — even for a few moments — keep a pet inside a hot car.