Climate Matters: Rising nighttime temperatures pose health risks this Fourth of July

"If it's hot, it's hot," says Tammy Adkins, a Community Wellness Nurse at Boone Health. "It gets cooler when the sun goes down, but that doesn't mean that it's not still dangerous."

Triple-digit heat is top of mind this Fourth of July, but the danger doesn't end when the sun goes down. As you head out for fireworks and cookouts, the overnight hours may be just as risky as the afternoon.

That risk is growing. In Columbia, overnight low temperatures have warmed by 3.1 degrees Fahrenheit since 1970 according to Climate Central, and nights are warming faster than days as the climate changes.

Climate Central's Climate Shift Index (CSI) also reveals the fingerprints of climate change on this holiday heat wave. Overnight temperatures on Saturday will be about 8 degrees warmer than normal, with a CSI value from 3 to 5 across Mid-MO. That means climate change boosted the odds of this nighttime heat by 3 to 5 times.

Fewer cool hours overnight mean less time for the body to recover, especially for anyone spending hours outside waiting for fireworks to start.

Some groups also face a higher risk, including the very young or old and those with chronic conditions. "Heart disease might make you more susceptible because your heart's working harder in the heat," Tammy says. "Athletes, people who work outside, and people who are pregnant might be more at risk."

Tammy says the best practice is to simply monitor symptoms. "The biggest tell is going to be your individual symptoms. If you're having symptoms of heat illness, then you don't ignore it just because, well, it's not a hundred degrees," she says.

The first symptom is typically heat cramps, an early sign of dehydration. That can progress to dizziness, nausea, fatigue, and fainting. "Then, when we get to heat stroke, if you start having altered mental status like confusion or changes in speech or behavior, that would be more of a medical emergency," Tammy warns.

Health officials say the fix is simple, even if it's easy to forget on a holiday night: stay hydrated, take breaks in air conditioning, and don't assume it's "cooled off" just because the sun's down.