"This has been pretty hot, and we haven't hit August. It has been really hot working on this concrete and asphalt," said Marvin Gillespie, Missouri Department of Transportation Department's maintenance superintendent for Charleston, Sikeston and East Prairie.
Missouri counties affected by the heat include Stoddard, Scott, Mississippi and New Madrid. Missouri counties further south were under a heat advisory, meaning the heat index went over 105 degrees in those counties.
David Humphrey, lead forecaster for the National Weather Service in Paducah, Ky., said heat index is a measure of the effect of the air temperature and the humidity and what that feels like to your body.
"So the air temperature might be 90, but when you factor in the humidity, it feels like 100," Humphrey said.
Temperatures today should be in the upper 80s. Clouds are expected to dominate with a 30 percent chance of showers and thunderstorms today and a 50 percent chance tonight, according to weather service forecasts. There's also a chance of rain Thursday.
"The actual high temperatures will be in the lower 90s and by the rest of the week. The humidity is sticking around," Humphrey said.
Humphrey said the Southeast Missouri region is in a "nice summer pattern."
"We always see 100-degree days in the summer. You call them the dog days of August for a reason," Humphrey said.
On Tuesday, Gillespie, who is working on Interstate 57 this week, said each year he has to remind fellow employees to exercise caution when working in the heat.
"We make sure crews have plenty of water and some Gatorade -- not a lot of Gatorade. We encourage them to take frequent breaks. We keep a pretty good eye on everybody," Gillespie said.
Crew members also wear head sweat bands with ice in them, Gillespie said.
"About three years ago, we had one person who almost had a heatstroke. He was working too hard and forgot about the heat," the 23-year MoDOT employee recalled.
Cramps, weakness, dizziness, vomiting, nausea, headaches are all common symptoms of heat-related illnesses.
According to Travis Fuller, MoDOT district safety and health manager, it takes about five to seven days for a human to adjust to heat. During which time the body will undergo a series of changes that will make continued exposure to heat more endurable.
"On the first day of work in a hot environment, the body temperature, pulse rate, and general discomfort will be higher," Fuller said in a news release. "With each succeeding daily exposure, all of these responses will gradually decrease, while the sweat rate will increase. When the body becomes acclimated to the heat, the worker will find it possible to perform work with less strain and distress."
Gradual exposure to heat gives the body time to become accustomed to higher environmental temperatures. Heat disorders in general are more likely to occur among workers who have not been given time to adjust to working in the heat or among workers who have been away from hot environments and who have gotten accustomed to lower temperatures, according to Fuller.
"Hot weather conditions of the summer are likely to affect the worker who is not acclimatized to heat. Workers who return to work after a leisurely vacation or extended illness may be affected by the heat in the work environment," Fuller said.
To protect yourself from heat stress, follow these guidelines provided by Fuller:
-- Be familiar with the early warning signs of heat stress and take immediate action when they are noted.
-- Drink plenty of fluids to prevent dehydration.
-- Remember, if you have not been in hot conditions for a while, or you are returning from vacation, your response to heat will not be as good as when you are "acclimatized."
-- Work smart in the heat. Don't over do it.