Learning can be difficult, even under the best conditions, and most Hawaii public school children don’t have anything close to the best condition in their classrooms.

It’s September, which is still the thick of summer in the islands, and thanks to the year-round academic year, the students already have been struggling with the heat for weeks. The prospect of air conditioning in every classroom probably sounds dreamy to them.

The reality is that fulfilling such a promise would cost an estimated $1 billion. A rally planned for Sept. 26, led by students and teachers, surely will garner public sympathy, but the reality is there is nowhere near the money in state coffers to underwrite an across-the-board air-conditioning upgrade.

What remains the most practical approach is fast-tracking air conditioning in the hottest of the hot classrooms, where fans and other lesser improvements just can’t do the job, and focus on less expensive upgrades in the near term for schools further down the list.

That is basically the strategy of the state Department of Education, although money to carry it out has been short in recent budgetary cycles. All the same, the Legislature should continue to support that mission rather than expand it more broadly to a statewide push.

Funding should be provided in a way that produces the most improvement for the most schools as soon as possible, and in many cases it’s more realistic to tailor the upgrades to the needs and capacity of each school.

This means principals should be given as much leeway as possible, within the bounds of state procurement laws, to craft the solutions for their campuses. Schools also should be supported in efforts involving parents, businesses and others in the communities to cooperate in fundraising efforts, so that simpler improvements could be made more quickly.

The 2007 Legislature considered a statewide air-conditioning program but shelved it as too costly. The focus on the schools with the worst heat benefited Kihei, Pohakea and Lokelani elementaries; the first two schools are fully air conditioned, and Lokelani is midway through its upgrade. Other schools on the A-list: Hickam, Ewa Beach, Aikahi, Maili, Kamaile, Kaimiloa and Nimitz elementaries; Ilima Intermediate and Campbell High School.

The DOE estimates the cost per school as ranging from $3.5 million to $10 million, depending on the school size. If that sounds high, it is: According to the DOE, the price tag can rise in older buildings where electrical systems also need to be replaced.

This underscores why it makes sense to consider alternative methods. The DOE is in the process of installing ceiling fans in 150 Leeward Oahu classrooms, which should help.

Other alternative cooling projects receiving state funds include a series of heat-reduction modifications — such as "solar tubes" illuminating classrooms while the light is switched off — at Kahuku Intermediate and High School in 2010, at a cost of $311,000.

In addition to fans, Ewa Beach Elementary the same year also was tagged to get reroofed, improving insulation against the sun’s heat. Reports from the campus were that small improvements did make things more comfortable.

Nobody questions that the heat, extending beyond the traditional summer months in Hawaii, poses a real problem for public school students. However, if the goal is to lower temperatures for kids currently in the public school system, the state and school communities must pursue solutions to be put in place well before they sweat their way through to graduation.