Almost $300,000 has been raised at the halfway point of this year's 40 Hour Famine.

Kiwis are out in their droves to support the cause this weekend, with more than 123,000 signing up to the challenge including 740 school groups. The young New Zealanders have taken up a range of challenging set-ups, from fasting, to living in shelters made only from boxes.

The funds raised this year will go to help children and their families in Bangladesh, a country where 8 million children are malnourished.

Among them is a year 9 student from Otumoetai College, Makayla Torrey, who has battled heavy downpours in her attempt to run up and down Mount Maunganui 40 times.

"I'm cold and I've been through all my dry clothes but in a way it's good because part of the idea was to experience some of the exhaustion and fatigue that the children of Bangladesh feel in their day-to-day lives." 

Torrential rain is set to give teams more of a challenge, with 20 hours left on the clock for participants.