The maximum power dissipation of the TL084IDRE4 is 670mW at 25°C free-air temperature, but it can be derated to 5.6mW/°C above 25°C.
Yes, the TL084IDRE4 is rated for operation from -40°C to 125°C, but the maximum junction temperature is 150°C. Be sure to derate the power dissipation accordingly.
To ensure stability, add a 10nF to 22nF capacitor between the output and the inverting input (pin 2) to prevent oscillations.
Keep the input traces short and away from the output traces to minimize noise coupling. Use a ground plane and decouple the power supply with 0.1uF and 10uF capacitors.
While possible, it's not recommended to use the TL084IDRE4 as a comparator due to its relatively slow slew rate (0.5V/us) and limited output current (±20mA). Consider a dedicated comparator IC instead.