Hi, I have a nest device and the room temp shows up on the Overview page of Hassio. I can also use the devtools to use the entity ID and get the current temp.
Problem faced is trying to get current room temp through node red so I can use it in my Telegram bot. No matter what I try, cant seem to extract this data even though its right there 
New at this, thanks for any help.
Create a template sensor.
Add this to your configuration.yaml, change the entity name to your climate entity.
- platform: template
sensors:
woonkamer_temperatuur: #this will be the name of the sensor (sensor.woonkamer_temperatuur) change to whatever you like.
friendly_name: "Woonkamer Temperatuur"
entity_id: climate.woonkamer_thermostat #Change to your climate entity
unit_of_measurement: '°C'
value_template: "{{ state_attr('climate.woonkamer_thermostat', 'current_temperature') }}" # change 'climate.woonkamer_thermostat' to your climate entity
Template was the right choice and the example from Meelobee worked to get the data I needed.
Was able to use the template data in a (node red) “get_template” node and then send it through an “edit_text” node. This took a while till I realised the “edit_text” node has to be blank ie remove the text input field and then it will parse the contents of the previous “get_template” node to the Telegram send node.
hope this helps someone else, thanks for the help.