[Nexus 5 Q&A, Help & Troubleshooting] Hammer_Of_The_Gods:
Hi,

Another one...

You have a quadcore at 2,26 Ghz device, under certain conditions (heavy games, browsing in 4g, long run heavy tasks, etc...) it's absolutely normal that the phone runs hot... And you sais it by yourself "I am playing clash of clans for a prolonged period of time."...

In any case there is a thermal protection called thermal throttling that reduces the CPU freq, the number of cores online and the screen brightness when the CPU (and/or battery) reaches some different temperature ranges, so no worries...

And even if Franciscofranco modified the thermal management, the thermal throttle is always present (you can also adjust it to reduce the heat by decreasing the CPU temp limit before thermal throttling).

But guys... in all scenarios there is the thermal throttling, and it does its job when needed. In extreme conditions the phone shutdown itself to prevent any damage. This CPU can handle more than 100 °C. Use your phone as normal, as you need... Or don't use GPS, don't play games, don't run benchs...

As an example on how thermal throttling works:

sampling 5000

[battery_LCD_monitor]
algo_type monitor
sensor batt_therm
sampling 10000
thresholds 100000 340000 350000 360000 370000
thresholds_clr 50000 330000 340000 350000 350000
actions override override override override override
action_info 10000 7500 5000 2500 0

[SKIN_THERMAL_management_1]
algo_type monitor
sensor xo_therm_pu2
sampling 10000
thresholds 40000 42000 44000
thresholds_clr 38500 40500 42500
actions cpu+lcd cpu+lcd cpu+lcd
action_info 1958400+229 1574400+204 1190400+178

[battery_monitor]
algo_type monitor
sensor batt_therm
sampling 10000
thresholds 480000 550000
thresholds_clr 460000 500000
actions battery battery
action_info 2 3

[CPU0_MONITOR]
algo_type monitor
sensor cpu0
sampling 65
thresholds 115000
thresholds_clr 110000
actions shutdown
action_info 0

[CPU1_MONITOR]
algo_type monitor
sensor cpu1
sampling 65
thresholds 115000
thresholds_clr 110000
actions shutdown
action_info 0

[CPU2_MONITOR]
algo_type monitor
sensor cpu2
sampling 65
thresholds 115000
thresholds_clr 110000
actions shutdown
action_info 0

[CPU3_MONITOR]
algo_type monitor
sensor cpu3
sampling 65
thresholds 115000
thresholds_clr 110000
actions shutdown
action_info 0

[HOTPLUG-CPU1]
algo_type monitor
sensor cpu1
sampling 65
thresholds 105000
thresholds_clr 85000
actions hotplug_1
action_info 1

[HOTPLUG-CPU2]
algo_type monitor
sensor cpu2
sampling 65
thresholds 105000
thresholds_clr 85000
actions hotplug_2
action_info 1

[HOTPLUG-CPU3]
algo_type monitor
sensor cpu3
sampling 65
thresholds 105000
thresholds_clr 85000
actions hotplug_3
action_info 1

[PID-CPU0]
disable 1

[PID-CPU1]
disable 1

[PID-CPU2]
disable 1

[PID-CPU3]
disable 1

[PID-POPMEM]
disable 1

[SS-CPU0]
algo_type ss
sampling 65
sensor cpu0
device cpu
set_point 80000
set_point_clr 55000

[SS-CPU1]
algo_type ss
sampling 65
sensor cpu1
device cpu
set_point 80000
set_point_clr 55000

[SS-CPU2]
algo_type ss
sampling 65
sensor cpu2
device cpu
set_point 80000
set_point_clr 55000

[SS-CPU3]
algo_type ss
sampling 65
sensor cpu3
device cpu
set_point 80000
set_point_clr 55000

[SS-POPMEM]
algo_type ss
sampling 65
sensor pop_mem
device cpu
set_point 80000
set_point_clr 55000
time_constant 16

It's a quadcore at 2,26 Ghz completely enclosed without any additional cooling system, so...

It remembers me the Nexus 4 all these threads/questions about "pseudo" heating/overheating...

Like simms22 said check your temperatures and provide them to have an approach a bit more real, because "it feels hot", "it is overheating", etc... is very subjective (for example I go outdoor with a 2 °C room temperature, I take my phone stays indoor and I feel it "hot", I check the CPU temperature and it's at about 30 °C...if you know what I try to say even if it's not your case here but it's a general idea).

Also you provide more information like overclock? Undervolt? Governor (even if in Franciscofranco kernel there is only Interactive and Performance)?

:)