An ectotherm, from the Greek εκτός (ektós) "outside" and θερμός (thermós) "hot", is an organism in which internal physiological sources of heat are of relatively small or quite negligible importance in controlling body temperature. Such organisms (for example frogs) rely on environmental heat sources, which permits them to operate at very economical metabolic rates. Some such animals live in environments in which temperatures are practically constant, as is typical of regions of the abyssal ocean. In contrast where temperature varies so widely as to limit the physiological activities of other kinds of ectotherms, many species habitually seek out external sources of heat or shelter from heat; for example, many reptiles regulate their body temperature by basking in the sun, or seeking shade when necessary. In contrast to ectotherms, endotherms rely largely, even predominantly, on heat from internal metabolic processes.

In ectotherms, fluctuating ambient temperatures affect the body temperature. Such variation in body temperature is called poikilothermy, though the concept is not widely satisfactory and the use of the term is declining. In small aquatic creatures such as Rotifera, the poikilothermy is practically absolute, but other creatures have wider physiological options at their disposal, and they can avoid ambient temperature changes, or moderate their effects.

John Michael "Ozzy" Osbourne (born 3 December 1948) is an English heavy metal vocalist and songwriter, whose musical career has spanned over 40 years. Osbourne rose to prominence as lead singer of the pioneering English band Black Sabbath, whose dark and hard sound helped spawn the heavy metal genre. Due to Sabbath's dark style, Osbourne became known as the "Prince of Darkness". Osbourne is also known as the "Godfather of Heavy Metal".

In the early 2000s, Osbourne's career expanded when he became a star in his own reality show The Osbournes, alongside wife/manager Sharon and two of their three children, Kelly and Jack. A documentary about his life and career, God Bless Ozzy Osbourne, premiered in April 2011 at the Tribeca Film Festival and was released on DVD in November 2011. Osbourne has achieved multi-platinum status as a solo artist and with Black Sabbath and has sold over 100 million albums worldwide.

John Michael "Ozzy" Osbourne was born in Aston, Birmingham, England, on 3 December 1948. His father Jack worked shifts as a toolmaker at GEC. His mother Lillian worked for the car components firm Lucas. John was the fourth of six children. Ozzy had two brothers (Paul and Tony) and three sisters (Jean, Iris and Gillian); they lived in a small two bedroom home at 14 Lodge Road in Aston. The nickname "Ozzy" was first used when he was in primary school. Although called "John" by his first wife Thelma, Osbourne states that it has been a long time since he's recognised himself when called by his formal name.

Joseph "Joe" Satriani (born July 15, 1956) is an American instrumental rock guitarist of Italian origin, multi-instrumentalist and multiple Grammy Award nominee. Early in his career, Satriani worked as a guitar instructor, and some of his former students have achieved fame such as Steve Vai, Larry LaLonde, Rick Hunolt, Kirk Hammett, Andy Timmons, Charlie Hunter, Kevin Cadogan and Alex Skolnick. Satriani has been a driving force in music credited to other musicians throughout his career, as a founder of the G3 tour, as well as performing in various positions with other musicians.

In 1988, Satriani was recruited by Mick Jagger as lead guitarist for Jagger's first solo tour. In 1994, Satriani was the lead guitarist for Deep Purple. Satriani worked with a range of guitarists, including Steve Vai, John Petrucci, Eric Johnson, Larry LaLonde, Yngwie Malmsteen, Brian May, Patrick Rondat, Andy Timmons, Paul Gilbert, Adrian Legg, and Robert Fripp through the annual G3 Jam Concerts. He is currently the lead guitarist for the supergroup Chickenfoot. Since 1988, Satriani has been using his own signature guitar, the Ibanez JS Series, which is sold in music stores worldwide.

Jay Chou; (born 18 January 1979) is a Taiwanese musician, singer-songwriter, music and film producer, actor and director. In 1998 he was discovered in a talent contest where he displayed his piano and song-writing skills. Over the next two years, he was hired to compose for popular Mandarin singers. Although he was trained in classical music, Chou combines Chinese and Western music styles to produce songs that fuse R&B, rock and pop genres. He composes all his own songs, as well as songs for other singers.

In 2000, Chou released his first album, titled Jay, under the record company Alfa Music. Since then he has released one album per year except in 2009, selling several million copies each. His music has gained recognition throughout Asia, most notably in regions such as Taiwan, China, Hong Kong, Japan, Malaysia, Indonesia, India, Singapore, Thailand, Vietnam and in overseas Asian communities. He has sold more than 28 million albums worldwide up to 2010. He debuted his acting career in Initial D (2005), for which he won Best Newcomer Actor in both the Hong Kong Film Awards and the Golden Horse Awards, and was nominated for Best Supporting Actor by Hong Kong Film Awards for his role in Curse of the Golden Flower (2006). He produced the theme song for the film Ocean Heaven starring Jet Li. His career now extends into directing and running his own record company JVR Music.