A preliminary report from Cal Fire says flames and heat forced four firefighters to deploy emergency shelters Sept. 12, shortly after responding to the Valley Fire.
The plastic cases for two firefighters' shelters melted. One firefighter had to remove his gloves to open a shelter for both to share.
Battalion Chief Doug Ferro says the department is investigating the melting shelter cases.
"We were very shocked and we're definitely looking deep and further into this and why this happened," he says.
Ferro says the shelter cases are typical of those used in the industry.
Three firefighters suffered first and second-degree burns.
One firefighter has second and third-degree burns and has been unable to speak since the incident.
"Human skin blisters at about 131 degrees," he says. "We know our firefighters suffered second-degree burns. Your respiratory is compromised at 250. We know that the PVC lining of the bag of the shelter melts at 280. Our Nomex can withstand up to 800 degrees, which is the yellow jacket. So, there [were] signs of failure on that. There were some significant temperatures."
"We are, as an agency and as an industry, are still trying to adapt to what the fire behaviors are doing here in California," he says. "The level of fuel moistures are unprecedented. We're finding ourselves having to really evaluate our tactics."
Cal Fire says it expects to have the Valley Fire fully contained Tuesday evening.