High school athletes will spend more time this summer adjusting to the heat during preseason practices, which began Saturday.

New statewide heat acclimatization guidelines cover the first 14 days of practice for all high school sports.

The guidelines address ways to avoid heat-related illnesses by making sure athletes gradually are acclimatized to heat and humidity during preseason practices. Particular attention is paid to the importance of hydration and the amount of time spent practicing.

Rules also cover the gradual introduction of sport-specific equipment and physical contact, both of which elevate body temperatures.

“Most of our coaches are very cognizant of making sure the kids have water, take breaks,” Randy Tira, Leonardtown High School athletic director, said last week. Still, having official guidelines will help make sure the same precautions are taken across every sport at every school in Southern Maryland, he said.

The guidelines will most immediately affect football practice because of the protective pads and helmets players wear.

“They can’t get in football pads until Friday,” on the sixth day of practice, Tira said.

In the past, players usually would be in full gear by the third day of practice, he said.

Field hockey goalies, who also wear protective pads, also will not be able to dress in their gear until the sixth day.

“The intent is to do a gradual introduction of equipment,” said Andrew Roper, supervisor of physical education, health and athletics for St. Mary’s County public schools.

Another change, especially for football, will be longer rest periods between practices that occur on the same day.

During the first five days, teams are limited to a single practice — not to exceed three hours, including warm-up and cool-down periods. A one-hour walk-through is permitted later in the day once a three-hour recovery period has elapsed.

Starting on the sixth day, total practice and walk-through time is limited to five hours a day, with no single session exceeding three hours. If a team elects to have two practices on one day, the following day must be a single practice day or a rest day.

The preseason practice guidelines for Southern Maryland Athletic Conference high school athletes were developed using a model policy put in place by the Maryland Public Secondary Schools Athletic Association. The policy was in response to a bill passed unanimously in the spring by both houses of the Maryland General Assembly and signed into law by Gov. Martin O’Malley (D) that require county boards of education to develop the preseason-practice heat acclimatization guidelines.

The National Athletic Trainers’ Association in 2009 released heat acclimatization guidelines for secondary school practices. Since then, many states and school jurisdictions have adopted similar guidelines.

Roper said the guidelines developed this summer are aimed specifically at fall sports, but that conference supervisors plan to develop similar guidelines for winter and spring sports. Fall sport athletes are most susceptible to heat illness because the beginning of the season tends to be the hottest.

He said that although St. Mary’s County high school athletes have not suffered any severe heat illnesses, overheating has occurred.

“It’s been a topic of discussion around the country in the last one and a half or two years,” said Ned Sparks, executive director of the state association.

He said 30 high school athletes have died of heat-related issues during the past 15 years in the United States, nearly all of which could have been prevented with proper hydration and other precautions.

Sparks said that most, if not all, high schools in the state already likely had some kind of acclimatization schedule when sports seasons begin.

“I don’t think it was probably as slow as the policy is suggesting,” Sparks said, adding that for some schools, the new policy could result in significant changes.

Although the state does not have any sanctions to impose on schools that don’t follow the policy, Sparks said he expects all schools to adhere.

“God help you if you don’t do it and something happens,” he said. “You can’t unring that bell.”

Student-athletes can participate in official conditioning sessions weeks before official practices are allowed. Strict rules prohibit any type of scrimmages and even disallow equipment, such as sports balls, from being used during conditioning.

The new heat acclimatization guidelines do not specifically apply to conditioning, but can help illustrate the importance of paying attention to athletes as they work out, especially in hot temperatures.

Stefanie Langton works as a strength and conditioning coach at Great Mills High School. She said it is extremely important for athletes to stay hydrated, and that coaches need to monitor the hydration of their athletes as well as how long practices and workouts last.

She added written guidelines provide coaches with firm times of practice and other instructions, and are worth having.

“It makes for good breaks, downtime and recovery,” Langton said.