Many different types of energy can be converted into heat energy. Light, electrical, mechanical, chemical, nuclear, sound and thermal energy itself can each cause a substance to heat up by increasing the speed of its molecules. So, put energy into a system and it heats up, take energy away and it cools.
Alexander Alex Robert Hirsch (born June 18, 1985) is the creator and former executive producer of the American animated television series, Gravity Falls. He voiced two of the main characters, Grunkle Stan and Soos. He also voiced supporting and recurring characters such as: Old Man McGucket, Bill Cipher, the gnomes and many others.
Nicholas Alan Nick Gehlfuss (born January 21, 1985) is an American actor, known for his role in 2014 as Robbie Pratt in the fourth season of the Showtime comedy-drama Shameless. In 2015, he started starring as Dr. Will Halstead in the NBC medical drama Chicago Med. 1 Career.