As summer temperatures soar in Japan, companies are developing products to help protect people from heatstroke. And not just people, animals in zoos are also at risk.

Plastic products maker Starlite is offering a device that slips onto the head and connects to a smartphone app. It measures ambient temperature and humidity as well as heat from the wearer's forehead.

The app measures 4 levels of heatstroke risk.

It also alerts managers when workers wearing the device face dangerous temperatures.

Starlite official Higashijima Masatoshi says, "The risk of heatstroke varies between workplaces, while individuals also have different levels of susceptibility to heat." He says he hopes the device can help with adopting tailored measures to prevent heatstroke.

Health equipment maker Tanita has developed outside sensors that attach to walls to monitor temperature, humidity and other metrics.

The sensors use a mobile communication network to show risk in different areas on a map based on a six-level heatstroke index.

Tanita sees a market for the system at construction sites, factories, schools, and zoos.

Tanita official Yamaya Chiaki says, "The system will help users take proactive steps before conditions reach dangerous levels."