Was it the heat, the heavy uniforms, or the presence of the star?

Maybe it was all of these that left four girls at Chilton St James School light-headed and on the verge of fainting yesterday as the Prime Minister opened the Lower Hutt school's new science and technology block.

It was a hot, muggy morning as John Key was greeted by about 620 school girls singing the national anthem.

One overcome girl was led away to get some water and then seated at the back, away from all the excitement.

Later, as the pupils broke into song again, one of the choir girls had to be led to a table at the back for a glass of water.

She was soon joined by two others unable to continue standing.

Mr Key went inside to inspect the building, but later returned to meet and greet the girls.

"He's such an inspirational role-model," gushed one. "He's so cool," was another star-struck accolade.