The temperature topping 35C is bad news for smartphones and their batteries.
If you have noticed your phone battery dwindling quicker than usual today, it may be because your device is simply too hot. If batteries get too hot, they work harder to run, which drains them quicker. Persistent heat can also shorten your device's battery life.
Many smartphones have built-in mechanisms that will start to limit your phone when they get too hot. Apple iPhones, for example, will begin shutting down features, to prevent the phone from overworking in the heat, which would add to the battery's temperature.