Summers in central Texas can be a struggle between being really hot and being really just too damn hot. Relief is wherever you can find it — your air-conditioned car, your air-conditioned office or an ice-cold Lone Star or three.

For some cold-blooded Texans, though — and even some adventure-seeking outsiders — relief from the Texas heat is just a small jump away, into the cool, clean, clear waters of Jacob's Well. But it comes at a price.

As cool and as nice as it is, you have to be a little crazy to take that jump.

A Bustling Tourist Attraction

Jacob's Well is a spring in Hays County, an hour or so southwest of Austin, near the towns of Wimberley and Dripping Springs. The well is fed by the Trinity Aquifer, which pushes up water through the well and spills it into nearby Cypress Creek.

That cool water has lured locals and visitors to the Hill Country spot for hundreds of years. And, for almost that long, Jacob's Well has been a siren call for the adventurous, too. Daredevils leap from a nearby outcropping into the slim opening of the well. Free-divers probe the well, sometimes as deep as 100 feet, maneuvering into thin openings into underwater caves. Even Scuba divers, on occasion, make forays into what the Jacob's Well Exploration Project calls a "challenging, unforgiving environment." (Recreational Scuba is not allowed.)

What's considered serious fun for some — lounging around on the lip of the well, escaping the heat, spending time with friends — is a lifestyle to others. And it can be a deadly lifestyle.

The Dangers of the Well

Diego Adame, a 21-year-old from San Antonio, lost a flipper free-diving the caves deep in the well in July 2015 and had to cut away his weight belt to make it back to the surface before his breath ran out. He even captured a part of the dive on video.

"For a split second," he told the San Antonio Express-News, "I thought of death and myself dying that day."

At least eight or nine people have died at Jacob's Well — the exact number is hard to come by — which has prompted some people to call it one of the most dangerous diving spots in the world. Two young Texas men were caught in one of the well's caves and drowned in 1979. One diver's remains were flushed out of the well in 1981. The other's remains weren't recovered until 2000.

Writer Louie Bond tells some of the well's story on the visitwimberley site, in a piece called, "The Fatal Allure of Jacob's Well." He describes at least four caves deep in the well, some with openings so narrow that divers have to remove their tanks to get through. Bond also describes the recovery of one of the well's victims in 2000, made by a diver from the San Marcos Area Recovery Team:

"You couldn't tell up from down, left from right," Kathy Misiaszek says. "You couldn't see your gauges. You were scraping the bottom and banging your tanks on the top. You had nothing to fall back on except your training. We were rather relieved to get out."

The danger beneath is belied by the beauty of the place. But even up top, Jacob's Well can be dangerous for those who make it that way.

The well, by at least one estimate, is only about 13 feet wide at the opening. Yet many wannabe daredevils climb to the rocks overlooking the opening and jump straight into the well, into the upward current. Some dive. Some do flips. (It is a swim-at-your-own-risk environment, according to the Hays County Parks Department.)

Visiting the Well

In that part of Texas in August, temperatures routinely hover around 97 degrees during the heat of the day. Many days push higher than 100. In fact, in the hottest of summers, that part of Texas can string together days and days of 100+ temperatures.

If you're looking for relief from the heat, Jacob's Well is a great place to get it. But plan ahead because reservations are required. Swimming is allowed from 10 a.m. to 6 p.m., and all swimmers get two hours per reservation.

If adventure is what you're after, though, you should make sure cooler heads prevail.