PC fan getting very loud

[deloptes <deloptes@gmail.com>]

Fujitsu ESPRIMO Q520 when opening some sh*tty web sitesin firefox the fan
gets extremly noisy.
On a Fujitsu C700 with the same setup there is no such problem - although I
probably do not open these sites - but some other sites cause a lot of load
and still the fan is not getting so noisy.

Fujitsu ESPRIMO Q520 CPU

vendor_id       : GenuineIntel
cpu family      : 6
model           : 60
model name      : Intel(R) Core(TM) i5-4570T CPU @ 2.90GHz
stepping        : 3
microcode       : 0x28
cpu MHz         : 1421.711
cache size      : 4096 KB
physical id     : 0
siblings        : 4
core id         : 1
cpu cores       : 2
apicid          : 3
initial apicid  : 3
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl
xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl
vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic
movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm
cpuid_fault epb invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow vnmi
flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms
invpcid xsaveopt dtherm ida arat pln pts md_clear flush_l1d
bugs            : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf
mds swapgs itlb_multihit srbds
bogomips        : 5786.69
clflush size    : 64
cache_alignment : 64
address sizes   : 39 bits physical, 48 bits virtual