Unity上からiOS端末の発熱状態を取得する

ProcessInfoBridge.cs

using System.Runtime.InteropServices;

namespace iOSNative
{
    /// <summary>
    /// `ProcessInfo`のBridge
    /// </summary>
    /// <remarks>
    /// - https://developer.apple.com/documentation/foundation/processinfo
    /// </remarks>
    public static class ProcessInfoBridge
    {
        /// <summary>
        /// システムの熱状態を取得
        /// </summary>
        /// <returns>
        /// NOTE:
        ///  - iOS実機以外は常に`.Nominal`を返す
        /// </returns>
        public static ThermalState ThermalState
        {
            get
            {
#if !UNITY_EDITOR && UNITY_IOS
                return (ThermalState) ThermalStateNative();
#endif
                return ThermalState.Nominal;
            }
        }

        #region P/Invoke

        [DllImport("__Internal", EntryPoint = "thermalState")]
        static extern int ThermalStateNative();

        #endregion P/Invoke
    }
}

ProcessInfoBridge.mm

#import <Foundation/Foundation.h>

#ifdef __cplusplus
extern "C" {
#endif

// システムの熱状態を取得
// NOTE: マーシャリングの都合でintで返しているが、結果自体はNSProcessInfoThermalStateに準拠
// ref: https://developer.apple.com/documentation/foundation/nsprocessinfothermalstate?language=objc
int thermalState() {
    return (int) [NSProcessInfo.processInfo thermalState];
}

#ifdef __cplusplus
}
#endif

ThermalState.cs

namespace iOSNative
{
    /// <summary>
    /// システムの熱状態
    /// </summary>
    /// <remarks>
    /// - https://developer.apple.com/documentation/foundation/processinfo/thermalstate
    /// </remarks>
    public enum ThermalState
    {
        /// <summary>
        /// The thermal state is within normal limits.
        /// </summary>
        Nominal,

        /// <summary>
        /// The thermal state is slightly elevated.
        /// </summary>
        Fair,

        /// <summary>
        /// The thermal state is high.
        /// </summary>
        Serious,

        /// <summary>
        /// The thermal state is significantly impacting the performance of the system and the device needs to cool down.
        /// </summary>
        Critical,
    }
}