NFL training camps start on July 24, 2013, during the peak of summer's sweltering heat.
In the heat wave that has been gripping the Midwest and Northeast this week, peak AccuWeather RealFeel® temperatures have soared as high as 110-115 degrees during the afternoon hours. This type of heat is extremely dangerous and not uncommon during the late July and early August.
Heat stroke is a major issue in athletics, particularly in high school athletics where a third of schools do not have an athletic trainer on staff, Douglas Casa, chief operating officer at the Korey Stringer Institute at the University of Connecticut, said.
He added that heat stroke is 100 percent survivable if you get the affected person's temperature under 104 degrees with 30 minutes of collapse.
A number of steps are needed to prevent heat illness from occurring, starting with becoming adjusted to the climate and practice work.
Miami Dolphins' Brian Hartline takes a drink during NFL football minicamp Thursday, June 13, 2013, at the team's training facility in Davie, Fla. (AP Photo/J Pat Carter)
"Intensity causes the injury," Head Athletic Trainer Scott Anderson of the University of Oklahoma and the president of the College Athletic Trainers' Society, said.
Acclimatizing athletes to the heat and humidity takes about 10 days to two weeks with a progressive approach to training, Anderson said.
"At the initial start, athletics may lack fitness and so you don't start hard, intense action," he said. "It's more an intensity problem than environmental."
Forty-one high school football players in the United States have died from exertional heat stroke since 1995, according to data cited by the National Federation of State High School Associations.
"Those were alarming numbers to us," Associate Executive Director Melissa N. Mertz of the Pennsylvania Interscholastic Athletic Association said.
Most deaths occur during the first four days of practice in August, Casa said.
High school athletes are susceptible because of varied fitness levels, particularly among linemen who tend to be overweight and out of shape, Casa said.
"Linemen are a very unique population. They are out of shape on a sports field, but they are a positive thing in the sport. But the day they stop playing, they would be considered obese," he said.
The PIAA has developed its first heat acclimatization rule for football, which takes effect for the 2013 season.
"There are some things we can't control in a contact sport like football but, with heat-illness deaths, we can take measures to prevent it from happening. It's necessary to keep kids safe," Mertz said.
The PIAA oversees more than 580 high school football programs in four classifications.
The new rule gives an option to football coaches: They can either do a three-day acclimatization program with no contact drills before the official first day of practice on Aug. 12 or do the acclimatization program the first week of practice.
The Pennsylvania rule took a year to create with the aid of coaches, district officials and sports medicine experts, Mertz said.
Pennsylvania, however, is one of 40 states that do not follow national guidelines issued in 2009 by the National Athletic Trainers Association (NATA), said Certified Athletic Trainer Dave Csillan, who is the head athletic trainer at Ewing High School in Ewing, N.J, and one of the co-chairs of the task force that worked on the NATA guidelines.
"[Pennsylvania] doesn't have much substance," he said. "It has a three-day acclimatization; ours in a 14-day period which is evidence-based."
Still coaches and other state association have the mentality of "It can't happen to us," Csillan said.
"Until we have 100-percent compliance with the guidelines, we're not doing okay," he said. "One death from catastrophic injury due to heat illness is too many."
The NFL and the NCAA established heat rules in 2011 and 2003, respectively. The football rule was part of the league's collective bargaining agreement.
The Korey Stringer Institute was founded after the 2001 death of Korey Stringer, a Minnesota Vikings and Pro Bowl lineman who died from exertional heat stroke.
Minds and policies do change when the liability issue is raised, Csillan said.
"Why haven't you followed the national guidelines," Csillan said of one question attorneys would probably ask of school districts and state associations.
On-field coaches need to be able to identify signs and symptoms of exertional heat stroke and seek immediate treatment of the affected athlete.
"[At Oklahoma], we have a cold tank at our practice facility which can be taken to the athlete to immerse them in cold water between 45 and 60 degrees," Anderson said.
Csillan said he uses a heat tracker to monitor air temperature, relative humidity and other factors and may modify the Ewing football practice schedule based on the information.
Athletes need rest breaks with shade, fluids and ice towels available to help with cooling. Fluids are also important for athletes during, before and after practices.
Coaches, however, should not think fluids provide immunity, an antidote, Anderson said.
"It's the intensity of the work," Anderson said.
More snow is on the way for Cleveland late this weekend.
Temperatures are not expected to get above the freezing point for the Seattle area this weekend.
The worst of the ice headed to the eastern U.S. will focus on the I-81 corridor from Virginia to southern Pennsylvania.
While heavy snow and ice are not expected to fall over much of the Midwest Sunday into Monday, some slippery roads and travel disruptions are likely.
As the saying goes, no two snowflakes are exactly alike. Russian photographer Alexey Kljatov's collection of high-resolution magnified flakes makes this widely-held belief more convincing.
Fresh cold and the return of Santa Ana winds are in store for Southern California to start the new week.
Elkton, MD (1963)
Jet liner exploded near Elkton, MD killing all 81 on board. Lightning is believed to have caused the explosion of residual fuel under one of the outboard wing tanks as plane passed through a vicious thunderstorm.
LaMesa, CA (1938)
100 degrees, warmest ever in US for Dec. Downtown LA had 91.7 degrees, only 90 degree reading in December.