Images and timeline supplied by Dave Clarke
This pop group, initially called Unit 5, was formed in 1963.
The line-up then was: Steve Harris - drums, Kevin Montague - lead guitar, Graham Thorn - rhythm guitar, Dave Clarke - bass guitar.
The name was changed, to "Sights Unnoticed":
Here they are 'top of the bill' at St. Augustines hall.
In 1965, they became "This Heat"...
...and in 1966, the name was changed again, to "The Heat":
"The Heat" line-up was: Alan Brewer - lead guitar/vocals, Graham Thorn - rhythm guitar, Dave Clarke - bass guitar, Dave H(?) - drums, Don Osborne - vocals.
Some moody promotional photos for The Heat, taken in 1965 at a disused railway station (click over each image to enlarge):
A ticket for a CSTS Dance in July 1966, featuring "The Heat":