The summer-borns run low on the heat in the winter, but when the heat comes, the summer-born can take in more heat.
(The summer-borns; run; low; L:on the heat; T:in the winter) (the heat; comes; ) (the summer-born; can take in; more heat; T:when the heat comes)
The summer-borns the heat the summer-born
run comes can take in
low L:on the heat T:in the winter
more heat T:when the heat comes