If a race or contest is adead heat, two or more competitors are joint winners, or are both winning at a particular moment in the race or contest. In American English, you can say that a race or contest is in adead heat.
The race ended in a dead heat between two horses.
A national poll shows the presidential race in a dead heat.
dead heat in British English
noun
a.
a race or contest in which two or more participants tie for first place
b.
a tie between two or more contestants in any position
dead heat in American English
a race in which two or more contestants reach the finish line at exactly the same time; tie