Mexico City - An eight-year-old girl from Chiapas has been awarded a prestigious science prize for a solar water heater she designed and made.

Xóchitl Guadalupe Cruz López of San Cristóbal de las Casas received the ICN Women's Recognition Award from the Institute of Nuclear Science at the National Autonomous University (UNAM). It is the first time the prize has been awarded to a child.

Xóchitl explained that she was motivated to invent her project because of the cold climate in her home town. "In San Cristóbal it's very cold most of the year so if people shower with cold water they can get sick with respiratory illnesses and constantly have to go to the doctor," she said.

Xóchitl consequently set out to design and make a low-cost water heater that doesn't harm the environment and is accessible to people of limited economic means.

"I want to help with my knowledge because there are a lot of poor people here," she said.

Xóchitl started with some basic sketches in her notebook but soon progressed to the stage when she was ready to gather the materials required for her homemade creation.

The young scientist explained that her solar heater is made of a 15-meter black hose, 10 PET bottles that she painted black, plastic cable ties, a wooden base, black nylon and recycled glass.

"I used glass doors from a broken cooler to create a greenhouse effect," Xóchitl explained.

The heater, which she installed on her home's rooftop, has the capacity to heat 10 liters of water to between 35 and 45° C.

Xóchitl's father Lucio, an indigenous education teacher at a local pre-school, encouraged his daughter during each step of the process and said he was quite pleased with what she has achieved.

"I'm very proud of my daughter because here in Chiapas it's very difficult to excel in science... As teachers we don't have that specialization and we're finding out little by little how to teach the young ones. The truth is that we've learned a lot with her," he said.

Xóchitl received support to complete her heater from the UNAM 'Adopt a Talent' Program, which encourages students from pre-school to high school to undertake scientific projects.

Apart from science, she also has a passion for soccer and mathematics and hopes one day to get a doctorate in the latter. But before then she has more immediate goals to achieve.

"My brother and I want to improve the heater," she explained.