With over 65 years of specialized HVAC system experience, SIGMA develops and designs sustainable class-leading heating and cooling solutions for mining, industrial, defense, and rail maintenance industries. Using custom designs and implementing significant innovations in control rooms, operator cabins, field medical, communication, and maintenance shelters – including armored personnel transport – SIGMA is renowned for absolute reliability and uncompromised performance in critical applications. Since designing its first air conditioning system for rail cars operating in harsh conditions in 1960, SIGMA remains a global leader in track design and maintenance, providing superior solutions to meet any extreme environment.