Dallas has seen a solid month of triple-digit temperatures, and 15 states are under National Weather Service heat advisories. To put those figures into some historical and scientific context, here's a round of hot-weather factoids. If you're in one of those 15 sweltering states, please drink a glass of water while you read them.

• NOAA has records of heat-related fatalities going back to 1986. For the first decade of data, the number of deaths did not top double digits until a disastrous 1995, when 1,021 people died. According to NOAA, about 700 of those deaths were in Chicago.
• Between 1986 and 1997, the median annual number of heat-related fatalities was 36. Between 1998 and 2010, it was 158.
• Seven high temperature records were broken Wednesday, and six were tied in Oklahoma, Kansas, Texas, Arkansas and Missouri.
• In parts of Missouri, the previous record was from the day before. Wednesday's high of 110 degrees beat out the all-time high of 106 that was set Tuesday.
• Participants in the raw foods movement do not eat food that has been prepared at temperatures greater than 104 degrees Fahrenheit. They should therefore steer clear of picnicking in Dallas or Oklahoma City, where today's forecast high is 110 degrees.
• Scientists say the average temperature on Earth during the Cretaceous period was just a chilly 82 degrees, though individual locations were much hotter.
• Apple recommends not operating its iPod Touch, iPad and iPhone in temperatures greater than 95 degrees. They can be stored at up to 113 degrees, but parked cars get hotter than that.