Not real sure we understand your question, are they heat resistant? If you are thinking of wearing these in a fire, than the answer is no they are not, NFPA certified firefighting boot
This was copied from Haix web site,
HAIX Secura Liner
Footwear inner liner which will never pull out or wrinkle up over time; lining is firmly secured and sealed along with the upper leather beneath the sole.
HAIX Climate System
Permits air circulation with every step – moist air is released and fresh air comes in through the vent holes at the top of the boot.
HAIX FP System
Flex Protection System: Leather reinforcement over the heel bend which protects this softer and more flexible leather from chafing.
HAIX AS System
Supports the arch of the foot in its natural, ideal position
Protective Toe Cap
Anatomically formed and well-padded composite protective toe cap.
Puncture resistant, non-metallic to meet ASTM F2413-11 and CAN/CSA Z195-2009 standard for personal protection – protective footwear
Brown oiled nubuk leather, waterproof, hydrophobic, and breathable.
GORE-TEX footwear, 4 layers with inner Cambrelle lining, abrasion resistant, softly padded with functional non-woven fabric. Waterproof, breathable, and chemical resistant.
Non-metallic puncture protective sole.
Anatomically formed, quick change, machine washable insert with excellent moisture absorption and quick drying qualities.
Non-woven footbed absorbs sweat and moisture.
Integrated heel bend, low friction lacing elements, TPU toe cap, no side seams, and reinforcement in the toe area.
Extended Wear Program
Out of warranty footwear can be refurbished with original factory parts through a resole package. This package includes any necessary replacement or repair of stitching, profiled rubber toe caps, soles, and insoles. Footwear will be cleaned and deodorized.
Answered on 8/8/2014 by Bg